Crystal structure, Raman spectroscopy, far-infrared, and microwave dielectric properties of (1-x)La(MgSn){sub 0.5}O{sub 3}-xNd(MgSn){sub 0.5}O{sub 3} system
- Department of Physics, Indian Institute of Technology-Madras, Chennai 600 036 (India)
- Departamento de Fisica, ICEx, UFMG, CP 702, Belo Horizonte, Minas Gerais 30123-970 (Brazil)
The complex perovskite system (1-x)La(MgSn){sub 0.5}O{sub 3}-xNd(MgSn){sub 0.5}O{sub 3} with the composition (x=0-1) was prepared by the solid state reaction method. Structural and spectroscopic studies were carried out to understand the variation of dielectric properties with x. Rietveld refinement was carried out with the initial model obtained by using the structure prediction and diagnostic software. The symmetry of the compositions was determined to be monoclinic with space group P2{sub 1}/n, which corresponds to the a{sup -}a{sup -}c{sup +} tilting system, and the long-range order parameter was found to decrease with an increase in neodymium concentration. Raman spectra were analyzed by fitting the A{sub 1g}-like mode to a Lorentzian peak shape. Intrinsic dielectric parameters were estimated by fitting infrared reflectance spectra with the four-parameter semiquantum model. Transverse optic phonon mode strengths and average phonon damping were calculated. The origin of increase in the intrinsic loss with the composition variation is discussed. Microwave measurements were carried out in the frequency range of 9-11 GHz. The dielectric constant decreases and the temperature coefficient of resonant frequency becomes less negative with the increase in neodymium concentration.
- OSTI ID:
- 21137169
- Journal Information:
- Journal of Applied Physics, Vol. 103, Issue 8; Other Information: DOI: 10.1063/1.2902932; (c) 2008 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
Similar Records
Effect of crystal structure and cationic order on phonon modes across ferroelectric phase transformation in Pb(Fe{sub 0.5-x}Sc{sub x}Nb{sub 0.5})O{sub 3} bulk ceramics
First-principle calculation and assignment for vibrational spectra of Ba(Mg{sub 1/3}Nb{sub 2/3})O{sub 3} microwave dielectric ceramic
Related Subjects
CERAMICS
DIELECTRIC MATERIALS
GHZ RANGE 01-100
INFRARED SPECTRA
LANTHANUM COMPOUNDS
MAGNESIUM COMPOUNDS
MICROWAVE RADIATION
MONOCLINIC LATTICES
NEODYMIUM
NEODYMIUM COMPOUNDS
ORDER PARAMETERS
PERMITTIVITY
PEROVSKITE
PHONONS
RAMAN SPECTRA
RAMAN SPECTROSCOPY
SPACE GROUPS
TEMPERATURE COEFFICIENT
TIN COMPOUNDS