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Title: Electrical conductivity anomaly and X-ray photoelectron spectroscopy investigation of YCr{sub 1−x}Mn{sub x}O{sub 3} negative temperature coefficient ceramics

Electrical conductivity anomaly of perovskite-type YCr{sub 1−x}Mn{sub x}O{sub 3} negative temperature coefficient (NTC) ceramics produced by spark plasma sintering (SPS) has been investigated by using defect chemistry theory combination with X-ray photoelectron spectroscopy (XPS) analysis. From the results of the lnρ-1/T curves and the XPS analysis, it can be considered that YCr{sub 1−x}Mn{sub x}O{sub 3} ceramics exhibit the hopping conductivity. The major carriers in YCrO{sub 3} are holes, which are compensated by the oxygen vacancies produced due to the introduction of Mn ions. The Mn{sup 4+} ion contents increase monotonically in the range of 0.2 ≤ x ≤ 0.5. The resistivity increases at first and then decreases with increasing Mn contents, which has the same varying tendency with activation energy. The electrical conductivity anomaly appearing in these ceramics may be due to the variation of Cr{sup 4+} and Mn{sup 4+} ions concentration as Mn content changes.
Authors:
 [1] ;  [2] ; ;  [1] ; ; ;  [3]
  1. Key Laboratory of Functional Materials and Devices for Special Environments of CAS, Xinjiang Key Laboratory of Electronic Information Materials and Devices, Xinjiang Technical Institute of Physics and Chemistry of CAS, Urumqi 830011 (China)
  2. (China)
  3. Kazuo Inamori School of Engineering, New York State College of Ceramics at Alfred University, Alfred, New York 14802 (United States)
Publication Date:
OSTI Identifier:
22257037
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 104; Journal Issue: 10; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ACTIVATION ENERGY; CERAMICS; CHROMIUM IONS; ELECTRIC CONDUCTIVITY; MANGANESE IONS; OXYGEN; PEROVSKITE; TEMPERATURE COEFFICIENT; VACANCIES; X-RAY PHOTOELECTRON SPECTROSCOPY; YTTRIUM