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Title: Critical behavior of resistivity in the pressure-induced first to second order transition in Pr{sub 0.6}Ca{sub 0.4}Mn{sub 0.96}B{sub 0.04}O{sub 3} (B=Co and Cr) polycrystals

We have investigated the hydrostatic pressure (P) dependence of the resistivity on Pr{sub 0.6}Ca{sub 0.4}Mn{sub 0.96}B{sub 0.04}O{sub 3} (B = Co and Cr) polycrystals. At ambient pressure, the temperature dependence of resistivity [ρ(T)] of both the samples show a first order paramagnetic insulator-ferromagnetic metallic transition at T=T{sub IM}. The application of P on both the samples increases the T{sub IM}, reduces the resistivity, and suppresses the hysteresis width, indicating a crossover from first to second order transition. The critical pressure, where the first-second order crossover takes place, are 2.02 and 2.40 GPa for Co and Cr doped samples respectively. The critical property of both systems around second order transition is investigated using Fisher-Langer relation and Suezaki-Mori method. The estimated critical exponents are close to the three-dimensional Heisenberg model for the Co doped sample suggesting short range interaction, and the exponents for the Cr doped sample follow the mean field theory suggesting long range ferromagnetic order. Further, the application of P suppresses the high temperature resistivity by reducing high temperature polarons in the case of the Cr doped sample, but it does not happen for the Co doped sample. The application of P helps to examine the stability of polarons in themore » high temperature regime.« less
Authors:
;  [1] ;  [2]
  1. Centre for High Pressure Research, School of Physics, Bharathidasan University, Tiruchirapalli-620024, Tamil Nadu (India)
  2. Department of Physics, 2 Science Drive 3, Faculty of Science, National University of Singapore, Singapore-117551 (Singapore)
Publication Date:
OSTI Identifier:
22490186
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1665; Journal Issue: 1; Conference: 59. DAE solid state physics symposium 2014, Tamilnadu (India), 16-20 Dec 2014; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; CALCIUM COMPOUNDS; CHROMIUM COMPOUNDS; COBALT COMPOUNDS; CRITICAL PRESSURE; DOPED MATERIALS; ELECTRIC CONDUCTIVITY; HEISENBERG MODEL; HYSTERESIS; INTERACTION RANGE; MANGANATES; MEAN-FIELD THEORY; PARAMAGNETISM; PHASE STABILITY; POLARONS; POLYCRYSTALS; PRASEODYMIUM COMPOUNDS; PRESSURE DEPENDENCE; PRESSURE RANGE GIGA PA; TEMPERATURE DEPENDENCE; THREE-DIMENSIONAL LATTICES