Ortak Dersler Bölümü

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Citation - WoS: 2
Academic Mobbing in Turkey and Suggestions for Solutions: Content Analysis of Graduate Theses
(Tuba-turkish Acad Sciences, 2019) Erdemir, Burcu; 192351; 01. Çankaya Üniversitesi
The effects of globalization on various sectors around the world are reflected in academia through competition, diminishing job security and faculty collegiality, and changing managerial understanding which causes academics to feel pressured to maintain the balance between teaching and research. This transformation inevitably has made the concepts explained by Foucault as "the power exerciser" and "the subject of power" more apparent, as demonstrated by conflicts and mobbing cases. The aim of this study is to review all the master's theses and doctoral dissertations written in Turkey to pin down what has been done until now on mobbing and to form a reference point. Upon searching for certain key words on the website of Council of Higher Education Thesis Center in June 2017, 655 theses on mobbing in various sectors with diverse participant groups were detected. After examining these theses in terms of their participants, it was found out that 29 of them, written between 2005 and 2017, addressed the issue of mobbing among academics. Of these, 26 theses, written between 2006 and 2016, were included in the study. The findings of these theses indicate that while there is 4-100% mobbing in the state and the foundation universities, younger people, singles, and women are more vulnerable to mobbing regarding self-expression, social relations, and communication, and they prefer to remain silent in the face of this issue. Besides, there is a negative relationship between mobbing and seniority, title, organisational justice, trust, commitment, and job-satisfaction. The primary causes of mobbing in academia are nepotism, poor leadership, unhealthy organisational culture, solidarity, andlack of communication. This study is expected to contribute to the formation of a conceptual framework about academic mobbing for the future studies and to expediting the process of taking measures for the eradication of the problem.
Adaptation of the Student Expectations of Online Learning Survey Revised (seols-R) Into Turkish
(Karadeniz Technical University, 2020) Dağhan, G.; Akkoyunlu, B.; Arslan, Ö.; 8539; 09.01. Ortak Dersler Bölümü; 09. Rektörlük; 01. Çankaya Üniversitesi
The aim of this study is to adapt the Student Expectations of Online Learning Survey Revised [SEOLS-R] developed by Harris, Larrier and Castano-Bishop (2011) into Turkish. For this purpose, the adaptation process of the scale, which consists of 7 factors and 43 items in the 5-point Likert structure, started first with the necessary permissions, and then a translation and cultural adaptation process was carried out. After the cultural adaptation process, the construct validity of the scale was tested with 411 students who study in distance education programs of Amasya University. After the construct validity findings, the reliability values of the scale were examined. In line with the findings, it was concluded that the Turkish version of the SEOLS-R scale is a valid and reliable measurement tool suitable for Turkish culture. © 2020 Karadeniz Technical University. All rights reserved.
Adaptive Estimation of Autoregressive Models Under Long-Tailed Symmetric Distribution
(Association for Computing Machinery, 2019) Yentür, B.; Bayrak, Ö.T.; Akkaya, A.D.; 56416; 09.01. Ortak Dersler Bölümü; 09. Rektörlük; 01. Çankaya Üniversitesi
In this paper, we consider the autoregressive models where the error term is non-normal; specifically belongs to a long-tailed symmetric distribution family since it is more relevant in practice than the normal distribution. It is known that least squares (LS) estimators are neither efficient nor robust under non-normality and maximum likelihood (ML) estimators cannot be obtained explicitly and require a numerical solution which might be problematic. In recent years, modified maximum likelihood (MML) estimation is developed to overcome these difficulties. However, this method requires that the shape parameter is known which is not realistic in machine data processing. Therefore, we use adaptive modified maximum likelihood (AMML) technique which combines MML with Huber’s estimation procedure so that the shape parameter is also estimated. After derivation of the AMML estimators, their efficiency and robustness properties are discussed through a simulation study and compared with MML and LS estimators. © 2019 Association for Computing Machinery.
Analysis and Mathematical Computation of Some Dynamic Function for Strontium Stannate
(Taylor & Francis Ltd, 2021) Askun, Ali Riza; 56475; 01. Çankaya Üniversitesi; 09. Rektörlük; 09.01. Ortak Dersler Bölümü
The frequency and full width at half maximum (FWHM) data of the A(g) Raman modes (95.4, 231.4 and 263.2 cm(-1)) in strontium stannate crystal have been analyzed using the Balkanski model and the fitting parameters were determined. Also, the isobaric Gruneisen parameter of A(g) Raman modes studied here was computed below the room temperature. This computation was performed from the unit cell volume and the observed frequency data of this crystal. Finally, values of the activation energy were extracted close to the structural phase transition temperatures of 160 and 265 K using the observed FWHM data of strontium stannate.
Analysis and Mathematical Computation of Some Dynamic Functions for the Guanidine Zinc Sulfate
(Taylor & Francis Ltd, 2021) Askun, A. R.; Kiraci, A.; 56475; 09.01. Ortak Dersler Bölümü; 09. Rektörlük; 01. Çankaya Üniversitesi
A power-law formula with a critical exponent alpha was used to analyze the anomalous behavior of the specific heat for guanidine zinc sulfate (GZS) crystal close to the phase transition temperature of T-c = 178.4 K. The obtained values of 0.13 and 0.14 for alpha below (T < T-c) and above (T> T-c) the phase transition temperature, respectively, were almost the same value of 0.13 (1/8) that predicted from the 3-D (sing model. Also, the internal energy U, the entropy S and the free energy G of this crystal were calculated as a function of temperature dose to the phase transition temperature of T-c = 178.4 K.
Citation - WoS: 2
Citation - Scopus: 3
Analysis of the Integrated Intensity of the Central Peaks Calculated as a Function of Temperature in the Ferroelectric Phase of Lithium Tantalate
(Vinca inst Nuclear Sci, 2018) Yurtseven, Hamit; Kiraci, Ali; 42475; 09.01. Ortak Dersler Bölümü; 09. Rektörlük; 01. Çankaya Üniversitesi
The integrated intensity of the central peak is calculated as a function of temperature in the ferroelectric phase (T < T-C) of nearly stoichiometric LiTaO3. This calculation is performed using the temperature dependence of the order parameter obtained from the mean field theory at temperatures lower than the transition temperature T-C (T-C = 963 K) of this crystal. The calculated values of the order parameter (squared) are fitted to the integrated intensity of the central peaks as observed from the Raman and Brillouin scattering experiments as reported in the literature in the ferroelectric phase of nearly stoichiometric LiTaO3. Our results are in good agreement with the observed behavior of LiTaO3 crystal. Because of the applications of LiTaO3 in several academic disciplines including the material science and thermal science, it is beneficial to investigate dynamic properties of this crystal such as the damping constant, inverse relaxation time and the activation energy as also we studied here.
Analysis of the Specific Heat and the Free Energy and Calculation of the Entropy and the Internal Energy of [N(ch3)4]2mnbr4 Close To the Phase Transition
(Taylor & Francis Ltd, 2021) Kiraci, A.; 42475; 09.01. Ortak Dersler Bölümü; 09. Rektörlük; 01. Çankaya Üniversitesi
The critical behavior of the specific heat and the Gibbs free energy of [N(CH3)(4)](2)MnBr4 was analyzed using the 'sing model close to the phase transition temperature of T-c = 276.5 K. Obtained value of alpha=0.02 from the Gibbs free energy and from the specific heat approximately 2.0 K and 1.4 K, respectively, below Tc (ferroelastic phase) and also deduced value of alpha= 0.04 from the specific heat approximately 0.3 K above T-c (paraelastic phase) can be compared with that predicted from mean field theory (alpha = 0). Also, the entropy and the internal energy of this crystal were predicted.
Citation - WoS: 8
Citation - Scopus: 8
Analysis of the Specific Heat and the Free Energy of [N(ch3)4]2znbr4 Close To the Ferro-Paraelastic Phase Transition
(Taylor & Francis Ltd, 2019) Kiraci, A.; 42475; 09.01. Ortak Dersler Bölümü; 09. Rektörlük; 01. Çankaya Üniversitesi
A power-law formula deduced from the Ising model was used to analyze the temperature dependence of the specific heat and the Gibbs free energy of [N(CH3)(4)](2)ZnBr4 compound in the vicinity of the phase transition temperature of T-C = 287.2 K. Obtained values of the critical exponents from the Gibbs free energy were consistent with that predicted from 2-d potts model ( = 0.3), while obtained values of from the specific heat in both ferroelastic and paraelastic phases were consistent with that predicted from the mean field theory ( = 0) in the vicinity of the phase transition temperature. This is an indication of that [N(CH3)(4)](2)ZnBr4 compound undergoes a second order type phase transition. Also, the enthalpy () and the entropy () of this crystal were calculated in terms of the extracted values of the critical exponent in both ferroelastic and paraelastic phases.
Bibliyografik Künye Karekodu Oluşturma Etkinliğine Yönelik Öğrenci, Öğretmen ve Okul Kütüphanecisi Görüşleri
(2019) Çetin, Nihal Menzi; Akkoyunlu, Buket; 8539; 09.01. Ortak Dersler Bölümü; 09. Rektörlük; 01. Çankaya Üniversitesi
Bilgi ve iletişim teknolojileri bilgiye erişme, bilgiyi paylaşma, iletme, bilgi ile iletişim kurma,yazma ve sunum yapma gibi işlemleri yerine getiren çeşitli araçlar sunmaktadır. Karekodlarmobil araçlarda kullanılan ve bilgiye erişimi hızlandıran araçlardan biridir. İlgi çekici vekullanımı kolay bir araç olarak karekodlardan eğitim ortamında faydalanılmakta ve olumlusonuçlar elde edilmektedir. Çeşitli araçları kullanarak bilgi becerilerini kazandırmayıamaçlayan ‘bilimsel iletişim öğretim programı’ ortaokul altıncı sınıf öğrencilerine yönelikgeliştirilmiş ve uygulanmıştır. Bu çalışmada bilimsel iletişim öğretim programında yer alanetkinliklerden biri olan bibliyografik künye karekodu oluşturma etkinliğine katılanöğrencilerin, öğretmenlerin ve okul kütüphanecisinin etkinliğe yönelik görüşleriincelenmiştir. Çalışma sonucunda söz konusu etkinliğin öğrencilerin bilgi kaynaklarına vekütüphaneye yönelik bakış açılarını olumlu etkilediği ve öğrencilerin kütüphane ortamındakarekodlardan yararlanabilecekleri faydalı bir etkinlik olduğu ifade edilmiştir.
Citation - WoS: 1
Citation - Scopus: 1
Calculation of the Frequency Shifts and Damping Constant for the Raman Modes (A1g, B1) Near the Tetragonal-Cubic Transition in Srtio3
(Tubitak Scientific & Technological Research Council Turkey, 2017) Yurtseven, Hasan Hamit; Kiraci, Ali; 42475; 09.01. Ortak Dersler Bölümü; 09. Rektörlük; 01. Çankaya Üniversitesi
Raman shifts of the soft mode A(1g) and the B-1 mode are calculated at various pressures at room temperature for the cubic-tetragonal transition (P-c = 9.5 GPa) in SrTiO3. This calculation is performed using the observed volume data through the mode Gruneisen parameters of A(1g) and B-1 which vary with pressure, by fitting to the experimental wavenumbers in this crystalline system. Calculated Raman shifts are then used as order parameters to predict the pressure dependence of the damping constant and the inverse relaxation time for the cubic-tetragonal transition in SrTiO3. Our predictions from the pseudospin-phonon coupling and the energy fluctuation models can be compared with the experimental measurements when available in the literature.
Citation - WoS: 3
Citation - Scopus: 2
Calculation of the Infrared Frequencies as a Function of Temperature Using the Volume Data in the Ferroelectric Phase of Nano2
(Taylor & Francis Ltd, 2014) Kiraci, A.; Yurtseven, H.; 42475; 09.01. Ortak Dersler Bölümü; 09. Rektörlük; 01. Çankaya Üniversitesi
We calculate the temperature dependence of the infrared frequencies of the TO and LO modes with the symmetries of A(1), B-1 and B-2 mainly in the ferroelectric phase of NaNO2. This calculation is carried out using the volume dependence of the infrared frequencies through the mode Gruneisen parameter in this crystal. The volume dependences of the infrared frequencies are fitted to the observed frequencies by using constant mode Gruneisen parameter in the ferroelectric phase of NaNO2. Our results show that this method of calculating the infrared frequencies describes the observed behaviour of NaNO2 adequately.
Citation - WoS: 4
Citation - Scopus: 5
Calculation of the Raman Frequency, Damping Constant (Linewidth) and the Relaxation Time Near the Tetragonal-Cubic Transition in Pbtio3
(Elsevier Gmbh, 2017) Yurtseven, H.; Kiraci, A.; 42475; 09.01. Ortak Dersler Bölümü; 09. Rektörlük; 01. Çankaya Üniversitesi
Frequencies, damping constants and the relaxation times of some Raman modes including the two soft modes are calculated as a function of pressure near the tetragonal-cubic transition in PbTiO3. Calculation of the Raman frequencies is performed using the observed volume data from the literature by means of the mode Gruneisen parameter at various pressures. Pressure dependence of the damping constant and the relaxation time is predicted using the pseudospin-phonon coupled model and the energy fluctuation model by considering that the Raman frequency can be taken as the order parameter (spontaneous polarization) for the tetragonal-cubic transition in PbTiO3. Expressions from both models for the damping constants are fitted to the observed Raman linewidths of the two soft modes and for the other Raman modes the damping constant and the relaxation time are predicted close to the transition. We find that damping constants diverge and the inverse relaxation time decreases for the soft modes with increasing pressure near the critical pressure (P-c similar to 11 GPa). The other Raman modes exhibit unusual critical behavior. Our results indicate that the observed behavior of the Raman frequencies can be predicted from the volume data through the mode Gruneisen parameter for the tetragonal-cubic transition in PbTiO3. The damping constant and the relaxation time for the Raman modes can also be predicted adequately using the pseudospin-phonon coupled model and the energy fluctuation model to explain the mechanism of the phase transition between the tetragonal and cubic phases in PbTiO3. (C) 2017 Elsevier GmbH. All rights reserved.
Citation - WoS: 5
Citation - Scopus: 6
Characteristic Features of Thermoluminescence in Neodymium-Doped Gallium Sulfide
(Wiley, 2018) Isik, M.; Ahmedova, F.; Guseinov, A.; Gasanly, N.; Guler, I.; 101531; 09.01. Ortak Dersler Bölümü; 09. Rektörlük; 01. Çankaya Üniversitesi
The thermoluminescence (TL) of neodymium-doped gallium sulfide (GaS:Nd) single crystals was measured from 10 K to room temperature with various heating rates between 0.2 and 1.0 K/sec. Two peaks centered at 70.9 K and 116.0 K were observed when using a heating rate of 0.8 K/sec. Initial rise and curve fitting methods were used to obtain information on trap activation energies. Activation energies of 94 and 216 meV were found for two analyzable peaks. The heating rate dependencies of TL intensities revealed that one of the observed peaks showed normal behavior according to the one trap-one recombination model, whereas the other model showed anomalous heating rate behavior. TL experiments were also carried out at different illumination temperatures from 10 to 32 K; maximum peak temperature remained almost the same at various illumination temperatures. This behavior indicated that the revealed trapping centers are single, discrete levels. The TL glow curves of undoped GaS crystals were also investigated and the effect of Nd doping on the TL characteristics of crystals is discussed in the manuscript.
Citation - WoS: 3
Citation - Scopus: 2
Characterization of Linear and Nonlinear Optical Properties of Nabi(Wo4)2 Crystal by Spectroscopic Ellipsometry
(Elsevier, 2024) Guler, I.; Gasanly, N. M.; Isik, M.; 101531; 09.01. Ortak Dersler Bölümü; 09. Rektörlük; 01. Çankaya Üniversitesi
NaBi(WO4)2 compound has been a material of considerable attention in optoelectronic applications. The present research, in which we examined the linear and nonlinear optical properties of NaBi(WO4)2 crystal using the spectroscopic ellipsometry method, elucidates the optical behavior of the crystal in detail. Our work provides a sensitive approach to determine the spectral characteristic of the crystal. The spectral dependence of various optical parameters such as refractive index, extinction coefficient, dielectric function and absorption coefficient was reported in the range of 1.2-5.0 eV. Optical values such as bandgap energy, critical point energy, single oscillator parameters were obtained as a result of the analyses. In addition to linear optical properties, we also investigated the nonlinear optical behavior of NaBi(WO4)2 and shed new light on the potential applications of the crystal. Absorbance and photoluminescence spectra of the crystal were also reported to characterize optical, electronic and emission behavior of the compound. Our findings may form the basis for a number of technological applications such as optoelectronic devices, frequency conversion, and optical sensors. This research contributes to a better understanding of the optical properties of NaBi(WO4)2 crystal, highlighting the material's role in future optical and electronic technologies.
Citation - WoS: 3
Citation - Scopus: 3
Characterization of N Rich-Silicon Nitride Thin Films Deposited by Pecvd
(Electrochemical Soc inc, 2023) Guler, I.; 101531; 09.01. Ortak Dersler Bölümü; 09. Rektörlük; 01. Çankaya Üniversitesi
Silicon nitride thin films are very important for their possible use in semiconductor industry and electronic applications. Changing the deposition parameters, silicon nitrides which have many varying optical properties can be produced. In this work, silicon nitride (SiNx) thin films were deposited on silicon substrates using Plasma enhanced chemical vapor deposition (PECVD) technique. The silane (SiH4) and ammonia (NH3) were used as reactant gases. Using these reactant gases, nitrogen (N) rich SiNx films were obtained. In order to get information about absorption and bond types in the films, films were analyzed by the help of Fourier transform infrared spectroscopy (FTIR) was performed. The refractive index, extinction coefficient and band gap energy of the films were changed from 1.86, 0 and 5.38 eV to 2.05, 0.0048 and 4.26 eV, respectively. Using the refractive index, composition of the films were estimated that is [N]/[Si] ratio of the films varied from 1.38 to 1.62. For possible applications of the SiNx films, learning the origin of the light-emission of the films is very important so the photoluminescence (PL) measurements were also used to see the luminescent of the SiNx films which is related to the electronic transitions between the K-center level and the conduction band tail states.
Citation - WoS: 21
Citation - Scopus: 25
Classification Models Based on Tanaka's Fuzzy Linear Regression Approach: the Case of Customer Satisfaction Modeling
(Ios Press, 2010) Sekkeli, Gizem; Koksal, Gulser; Batman, Inci; Bayrak, Ozlem Turker; 56416; 09.01. Ortak Dersler Bölümü; 09. Rektörlük; 01. Çankaya Üniversitesi
Fuzzy linear regression (FLR) approaches are widely used for modeling relations between variables that involve human judgments, qualitative and imprecise data. Tanaka's FLR analysis is the first one developed and widely used for this purpose. However, this method is not appropriate for classification problems, because it can only handle continuous type dependent variables rather than categorical. In this study, we propose three alternative approaches for building classification models, for a customer satisfaction survey data, based on Tanaka's FLR approach. In these models, we aim to reflect both random and fuzzy types of uncertainties in the data in different ways, and compare their performances using several classification performance measures. Thus, this study contributes to the field of fuzzy classification by developing Tanaka based classification models.
Citation - WoS: 9
Citation - Scopus: 14
Collaborations, Concepts, and Citations in Educational Technology: a Trend Study Via Bibliographic Mapping
(Springer, 2022) Soylu, Meryem Yilmaz; Akkoyunlu, Buket; Deryakulu, Deniz; Bardakci, Salih; 8539; 09.01. Ortak Dersler Bölümü; 09. Rektörlük; 01. Çankaya Üniversitesi
Research trends studies have emerged in education technologies (ET) to determine research manner and changes. Although the precedent examples dated back to the 1950s, trend studies within ET have gradually been increasing since the 1970s. This study aimed to examine the ET publications and research trends in a 5-year time period from 2014 to 2018. With a bibliographic mapping tool, namely VOSviewer, three research questions were addressed relating to collaborations, concepts, and citations in educational technology studies. The data set was extracted from ISI Web of Science databases and included 1690 articles published in six educational technology journals between 2014 and 2018. We used co-authorship analysis to determine the collaborating researchers' institutions and their geographical locations (countries) when they published the articles. A co-occurrence analysis was used to investigate concepts. Finally, a co-citation analysis was employed to determine the most cited papers and journals. Co-authorship analyses revealed that the number of articles published by researchers affiliated with institutions in the USA was the highest in the data set. According to co-occurrence analysis, online learning, especially in open learning environments, was the most studied concept. Moreover, co-citation analysis showed that the most frequently cited articles were published in Computers & Education. Additional findings, discussion, and limitations of the study were explained in the full text.
Citation - WoS: 4
Citation - Scopus: 8
Creating Infographics Based on the Bridge21 Model for Team-Based and Technology-Mediated Learning
(informing Science inst, 2019) Sullivan, Kevin; Akkoyunlu, Buket; Nuhoglu-Kibar, Pinar; 8539; 09.01. Ortak Dersler Bölümü; 09. Rektörlük; 01. Çankaya Üniversitesi
Aim/Purpose The main aim of this study was modeling a collaborative process for knowledge visualization, via the creation of infographics. Background As an effective method for visualizing complex information, creating infographics requires learners to generate and cultivate a deep knowledge of content and enables them to concisely visualize and share this knowledge. This study investigates creating infographics as a knowledge visualization process for collaborative learning situations by integrating the infographic design model into the team-based and technology-mediated Bridge21 learning model. Methodology This study was carried out using an educational design perspective by conducting three main cycles comprised of three micro cycles: analysis and exploration; design and construction; evaluation and reflection. The process and the scaffolding were developed and enhanced from cycle to cycle based on both qualitative and quantitative methods by using the infographic design rubric and researcher observations acquired during implementation. Respectively, twenty-three, twenty-four, and twenty-four secondary school students participated in the infographic creation process cycles. Contribution This research proposes an extensive step-by-step process model for creating infographics as a method of visualization for learning. It is particularly relevant for working with complex information, in that it enables collaborative knowledge construction and sharing of condensed knowledge. Findings Creating infographics can be an effective method for collaborative learning situations by enabling knowledge construction, visualization and sharing. The Bridge21 activity model constituted the spine of the infographic creation process. The content generation, draft generation, and visual and digital design generation components of the infographic design model matched with the investigate, plan and create phases of the Bridge21 activity model respectively. Improvements on infographic design results from cycle to cycle suggest that the revisions on the process model succeeded in their aims. The rise in each category was found to be significant, but the advance in visual design generation was particularly large. Recommendations for Practitioners The effectiveness of the creation process and the quality of the results can be boosted by using relevant activities based on learner prior knowledge and skills. While infographic creation can lead to a focus on visual elements, the importance of wording must be emphasized. Being a multidimensional process, groups need guidance to ensure effective collaboration. Recommendation for Researchers The proposed collaborative infographic creation process could be structured and evaluated for online learning environments, which will improve interaction and achievement by enhancing collaborative knowledge creation. Impact on Society In order to be knowledge constructors, innovative designers, creative communicators and global collaborators, learners need to be surrounded by adequate learning environments. The infographic creation process offers them a multidimensional learning situation. They must understand the problem, find an effective way to collect information, investigate their data, develop creative and innovative perspectives for visual design and be comfortable for using digital creation tools. Future Research The infographic creation process could be investigated in terms of required learner prior knowledge and skills, and could be enhanced by developing pre-practices and scaffolding.
Citation - WoS: 8
Citation - Scopus: 8
Damping Constant (Linewidth) and the Relaxation Time of the Brillouin La Mode for the Ferroelectric-Paraelectric Transition in Pbzr1-Xtixo3
(Ieee-inst Electrical Electronics Engineers inc, 2016) Kiraci, Ali; Yurtseven, Hamit; 42475; 09.01. Ortak Dersler Bölümü; 09. Rektörlük; 01. Çankaya Üniversitesi
The damping constant (linewidth) of the longitudinal acoustic (LA) mode is calculated as a function of temperature using the observed Brillouin frequencies of this mode from the literature for the ferroelectric-paraelectric transition (T-C = 657 K) in PbZr1-xTixO3 (x = 0.45). For this calculation of the damping constant, the pseudospin-phonon coupled model and the energy fluctuation model are used by fitting to the observed data for the Brillouin frequencies of the LA mode in the ferroelectric (T < T-C) and paraelectric (T > T-C) phases of this compound (x = 0.45). Values of the activation energy are deduced for both ferroelectric and paraelectric phases. The relaxation time is also obtained by means of fitting to the observed data from the literature for the inverse relaxation time at various temperatures in the paraelectric phase of PbZr1-xTixO3. The temperature dependences of the damping constant and of the relaxation time with the values of the activation energy that we have calculated indicate that the pseudospin-phonon coupled model and the energy fluctuation model are capable of describing the ferroelectric-paraelectric transition (T-C = 657 K) in PbZr1-xTixO3 (x = 0.45) adequately.
Citation - WoS: 3
Citation - Scopus: 4
Damping Constant and the Inverse Relaxation Time Calculated as a Function of Pressure Using the X-Ray Diffraction Data Close To the Cubic-Tetragonal Phase Transition in Srtio3
(Taylor & Francis Ltd, 2019) Kiraci, A.; Yurtseven, H.; 42475; 09.01. Ortak Dersler Bölümü; 09. Rektörlük; 01. Çankaya Üniversitesi
The damping constant is calculated as a function of pressure at room temperature using the normalized intensity as an order parameter near the cubic-tetragonal phase transition in SrTiO3. The observed X-ray diffraction data are used for the normalized intensities to calculate the damping constant () from the pseudospin-phonon (PS) coupled model and the energy fluctuation (EF) model, which is fitted to the observed FWHM data from the literature for comparison. Using the calculated values, the pressure dependence of the inverse relaxation time () is predicted close to the cubic-tetragonal phase transition in SrTiO3. Our calculated damping constant from both models explains the observed FWHM satisfactorily and our prediction of the inverse relaxation time can also be compared with the experimental measurements when they are available in the literature.

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