Field induced modification of defect complexes in magnesium-doped lithium niobate

Journal Article · Sun Dec 28 00:00:00 EST 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4905021· OSTI ID:22399161

Meyer, Nadège; Granzow, Torsten ^[1]

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1. Department of Materials Research and Technology, Luxembourg Institute of Science and Technology, 41 rue du Brill, L-4422 Belvaux (Luxembourg)

Dielectric constant, thermally stimulated depolarization currents (TSDC), and conductivity of undoped and 5% Mg-doped LiNbO{sub 3} single crystals between −100 °C and 200 °C have been investigated. A Debye-like dielectric relaxation with an activation energy of 135 meV is observed in the Mg-doped material, but not in undoped crystals. On heating this relaxation disappears near 140 °C and does not reappear after cooling. Anomalies observed in TSDC around this temperature are attributed to the motion of lithium vacancies, in agreement with conductivity measurements. It is proposed that in thermal equilibrium the electrons from the Mg{sub Li}{sup •} donors are trapped in (4Mg{sub Li}{sup •}+4V{sub Li}{sup ′}) defect complexes. High-temperature poling breaks these defect complexes. The transition of the liberated electrons between the Mg{sub Li}{sup •} donor centers and the Nb{sub Nb} forming the conduction band gives rise to the observed dielectric relaxation.

• OSTI ID: 22399161
• Journal Information: Journal of Applied Physics, Vol. 116, Issue 24; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ACTIVATION ENERGY
DEPOLARIZATION
DIELECTRIC MATERIALS
DOPED MATERIALS
ELECTRIC CONDUCTIVITY
ELECTRONS
HEATING
LITHIUM
LITHIUM COMPOUNDS
MAGNESIUM
MONOCRYSTALS
NIOBATES
PERMITTIVITY
RELAXATION
TEMPERATURE DEPENDENCE
THERMAL EQUILIBRIUM
TRAPPING
VACANCIES