Raman spectroscopy of CaTiO3-based perovskite solid solutions

2004 ◽  
Vol 19 (2) ◽  
pp. 488-495 ◽  
Author(s):  
H. Zheng ◽  
I.M. Reaney ◽  
G.D.C. Csete de Györgyfalva ◽  
R. Ubic ◽  
J. Yarwood ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Solid Solutions ◽  
Dielectric Resonators ◽  
Complex Perovskite ◽  
Microwave Dielectric ◽  
Ion Radius ◽  
A Site ◽  
End Members

Perovskite-structured solid solutions intended for use as microwave dielectric resonators were studied by Raman spectroscopy. Two distinct categories were investigated: (i) simple perovskite–simple perovskite solid solutions, that is, CaTiO3–SrTiO3 (CTST), CaTiO3–CaZrO3 (CTCZ), CaTiO3–NdAlO3 (CTNA), and CaTiO3–LaGaO3 (CTLG); and (ii) simple perovskite–complex perovskite solid solutions, such as CaTiO3–SrMg1/3Nb2/3O3 (CTSMN). In the latter category, the influence of A-site ion radius was also addressed by examining 0.5CaTiO3– 0.5LaMg1/2Ti1/2O3 (0.5CT–0.5LMT), 0.5SrTiO3 (ST)–0.5LMT, and 0.5BaTiO3 (BT)–0.5LMT. Raman data from the end members and solid solutions are compared, paying particular attention to F2g and A1g mode bands, often associated with ordering of B-site species.

Effect of bond valence on microwave dielectric properties of (Pb1−xCax)(Mg0.33Ta0.67)O3 ceramics

2001 ◽  
Vol 16 (3) ◽  
pp. 817-821 ◽  
Author(s):  
Heung Soo Park ◽  
Ki Hyun Yoon ◽  
Eung Soo Kim
Keyword(s):  
Dielectric Properties ◽  
Microwave Dielectric Properties ◽  
Bond Valence ◽  
Negative Deviation ◽  
Complex Perovskite ◽  
Microwave Frequencies ◽  
Microwave Dielectric ◽  
Dielectric Polarizability ◽  
A Site ◽  
The Relationship

The relationship between the dielectric properties of the complex perovskite (Pb1−xCax)(Mg0.33Ta0.67)O3 ceramics, where 0.45 ≤ × ≤ 0.60, and the dielectric polarizability, related to bond valences of A-site ions, was investigated at microwave frequencies. As the Ca content (x) increased, the deviation of the observed dielectric polarizabilities, calculated by the Clausius–Mosotti equation from the theoretical values calculated by the additivity rule of dielectric polarizability, decreased from −3% to −0.69%. It was found that this deviation was related to the bond valence of the A-site. Smaller negative deviation corresponded to the cations with lower bond valence, and larger negative deviation corresponded to the cations with higher bond valence. Also, the temperature coefficient of resonant frequency (TCF) was affected by the bond valence of the A-site, and then TCF decreased with decreasing bond valence of the A-site in ABO3 perovskite compounds.

1C-b Solid solutions with complex perovskite-type oxides as end members

2005 ◽  
pp. 130-136
Author(s):  
M. Adachi ◽  
J. Harada ◽  
T. Ikeda ◽  
S. Nomura ◽  
E. Sawaguchi ◽  
...  
Keyword(s):  
Solid Solutions ◽  
Complex Perovskite ◽  
End Members ◽  
Perovskite Type

Normal-relaxor ferroelectric modulation of a-site complex perovskite ferroelectric (K1/2Bi1/2)TiO3 by post-annealing

2017 ◽  
Vol 121 (1) ◽  
pp. 014101 ◽  
Author(s):  
Jinjian Guo ◽  
Mankang Zhu ◽  
Ling Li ◽  
Tianhe Qing ◽  
Cong Wang ◽  
...  
Keyword(s):  
Relaxor Ferroelectric ◽  
Complex Perovskite ◽  
Post Annealing ◽  
A Site

Polaron conduction loss in microwave dielectric ceramics

1999 ◽  
Vol 14 (2) ◽  
pp. 500-502
Author(s):  
Seungbum Hong ◽  
Eunah Kim ◽  
Han Wook Song ◽  
Jongwan Choi ◽  
Dae-Weon Kim ◽  
...  
Keyword(s):  
Quality Factor ◽  
Phonon Scattering ◽  
Dielectric Resonators ◽  
Frequency Range ◽  
Conduction Loss ◽  
Microwave Dielectric ◽  
Scattering Effects ◽  
Unloaded Quality Factor ◽  
Dielectric Ceramics ◽  
Polaron Conduction

It has been generally accepted that the product of the unloaded quality factor and resonant frequency is the universal parameter for comparison of dielectric resonators with different size.1,2 However, it is suggested in this study that this universal parameter should be modified due to the presence of the polarons. From the frequency dependence of the unloaded quality factor, it is possible to extract the factor determined only by the phonon scattering effects, and we denoted this parameter by Qs. It was found that the Qs parameter for ZrxSnzTiyO4 (ZST) and Ba(Zn1/3Ta2/3)O3 (BZT) ceramics showed constancy in the frequency range of 2–12 GHz, which supports the idea of polaron conduction loss contribution to the dielectric loss.

scholarly journals Review of Oxygen Vacancies in CeO2-doped Solid Solutions as Characterized by Raman Spectroscopy

2012 ◽  
Vol 28 (05) ◽  
pp. 1012-1020 ◽  
Author(s):  
LI Lan ◽  
◽  
HU Geng-Shen ◽  
LU Ji-Qing ◽  
LUO Meng-Fei
Keyword(s):  
Raman Spectroscopy ◽  
Solid Solutions ◽  
Oxygen Vacancies

scholarly journals FABRICATION AND PROPERTIES OF Co DOPED Bi0.5K0.5TiO3 – BiFeO3 SOLID SOLUTION

2018 ◽  
Vol 56 (1A) ◽  
pp. 197
Author(s):  
Nguyen Hoang Tuan
Keyword(s):  
Solid Solution ◽  
Raman Spectroscopy ◽  
Magnetic Properties ◽  
Crystal Structures ◽  
Solid Solutions ◽  
Sol Gel ◽  
Structure And Properties ◽  
Antiferromagnetic Ordering ◽  
Co Doped ◽  
Good Agreement

In this study, we present some results on the structure and properties of the solid solution of Bi0.5K0.5TiO3– BiFeCoO3 (BKT – BFCO) by Sol-gel method. Crystal structures of BKT – BFCO solid solutions were studies by XRD and Raman spectroscopy. The results were in good agreement with the previous reports of Bi0.5K0.5TiO3– BiFeO3 (BKT – BFO) and Bi0.5K0.5TiO3 – BiCoO3 (BKT – BCO) solid solutions. The magnetic properties were investigated via unsaturated M-H loop, which showed the competition of paramagnetic and antiferromagnetic ordering in BKT – BFCO. However, differing from the BKT – BFO and BKT – BCO solid solutions, the unclear values of saturated magnetism in BKT – BFCO raised the unexplained question, which needed further studies.

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