Mixed conduction and grain boundary effect in lithium niobate under high pressure

Journal Article · Mon Mar 30 00:00:00 EDT 2015 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4916828· OSTI ID:22398826

Wang, Qinglin ^[1]; Liu, Cailong; Han, Yonghao; Gao, Chunxiao ^[1]; Gao, Yang ^[1]; Ma, Yanzhang ^[2]

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1. State Key Laboratory of Superhard Materials, Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012 (China)
2. Department of Mechanical Engineering, Texas Tech University, Lubbock, Texas 79409 (United States)

The charge transport behavior of lithium niobate has been investigated by in situ impedance measurement up to 40.6 GPa. The Li{sup +} ionic conduction plays a dominant role in the transport process. The relaxation process is described by the Maxwell-Wagner relaxation arising at the interfaces between grains and grain boundaries. The grain boundary microstructure rearranges after the phase transition, which improves the bulk dielectric performance. The theoretical calculations show that the decrease of bulk permittivity with increasing pressure in the Pnma phase is caused by the pressure-induced enhancement of electron localization around O atoms, which limits the polarization of Nb-O electric dipoles.

• OSTI ID: 22398826
• Journal Information: Applied Physics Letters, Vol. 106, Issue 13; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ATOMS
CHARGE TRANSPORT
DIELECTRIC MATERIALS
ELECTRIC DIPOLES
ELECTRONS
GRAIN BOUNDARIES
IMPEDANCE
INTERFACES
LITHIUM COMPOUNDS
LITHIUM IONS
NIOBATES
ORTHORHOMBIC LATTICES
PERMITTIVITY
PHASE TRANSFORMATIONS
POLARIZATION
PRESSURE DEPENDENCE
PRESSURE RANGE GIGA PA
RELAXATION