Structural and magnetotransport properties of LaMn1−xCrxO3.00 „0ÏxÏ0.15…: Evidence of Mn3+-O-Cr3+ double-exchange interaction

L.B. MORALES; R. ALLUB; B. ALASCIO; A. BUTERA; A. CANEIRO

PHYSICAL REVIEW B

AMER PHYSICAL SOC

Lugar: New York; Año: 2005 vol. 72 p. 324413 - 434416

1098-0121

A comparative study of the structural, magnetic, and transport properties of LaMn1−xCrxO3.00 perovskitesamples
0
x
0.15 is reported. Resistivity measurements in the paramagnetic region show a semiconductortype behavior with a gap that decreases with Cr concentration and a large negative magnetoresistance. Thisbehavior can be understood through a simple model of the electronic structure of the alloy, which includesdouble exchange between Mn and Cr and a CPA type approximation. Comparison between experimentalresults and theory is included. We conclude that double exchange is responsible for the ferromagnetic interactionbetween Cr and Mn.