TY - JOUR
T1 - Low-temperature resistivity minima in colossal magnetoresistive (formula presented) thin films
AU - Kumar, D.
AU - Sankar, J.
AU - Narayan, J.
AU - Singh, Rajiv K.
AU - Majumdar, A. K.
PY - 2002
Y1 - 2002
N2 - The low-temperature magnetoresistance of (formula presented) (LCMO) thin films has been investigated using a four-probe dc technique with a 5 T superconducting magnet. Thin film samples of LCMO were prepared in situ using a pulsed laser deposition technique. The results obtained from the high-resolution low-temperature (5-50 K) measurements, carried out on various samples differing widely in their resistivities, have shown distinct minima at (formula presented) in the resistivity versus temperature plots for all fields. The depth of the resistance minima was found to increase with an increase in applied magnetic field (formula presented) while (formula presented) versus (formula presented) curves showed maxima at around 2 T. We have fitted the resistivity versus temperature data for all (formula presented) to an expression that contains three terms, namely, residual resistivity, inelastic scattering, and electron-electron (formula presented) interaction and Kondo effects. We conclude that the (formula presented) interaction effect is the dominant mechanism for the negative temperature coefficient of resistivity of these colossal magnetoresistance (CMR) materials at low temperatures.
AB - The low-temperature magnetoresistance of (formula presented) (LCMO) thin films has been investigated using a four-probe dc technique with a 5 T superconducting magnet. Thin film samples of LCMO were prepared in situ using a pulsed laser deposition technique. The results obtained from the high-resolution low-temperature (5-50 K) measurements, carried out on various samples differing widely in their resistivities, have shown distinct minima at (formula presented) in the resistivity versus temperature plots for all fields. The depth of the resistance minima was found to increase with an increase in applied magnetic field (formula presented) while (formula presented) versus (formula presented) curves showed maxima at around 2 T. We have fitted the resistivity versus temperature data for all (formula presented) to an expression that contains three terms, namely, residual resistivity, inelastic scattering, and electron-electron (formula presented) interaction and Kondo effects. We conclude that the (formula presented) interaction effect is the dominant mechanism for the negative temperature coefficient of resistivity of these colossal magnetoresistance (CMR) materials at low temperatures.
UR - http://www.scopus.com/inward/record.url?scp=84861114981&partnerID=8YFLogxK
U2 - 10.1103/physrevb.65.094407
DO - 10.1103/physrevb.65.094407
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AN - SCOPUS:84861114981
SN - 1098-0121
VL - 65
SP - 1
EP - 6
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 9
ER -