Mesoscopic thermodynamics of an inhomogeneous colossal-magnetoresistive phase
Equilibrium conductivity fluctuations of mesoscopic domains are found in film and bulk single-crystal manganite colossal magnetoresistive material. Temperature and field dependences of the Boltzmann factors for a collection of two-state fluctuators give measures of the magnetic moment and entropy differences between the states, and of the fluctuator volumes. The large resistance step size implies dramatic current inhomogeneities. Occasional anomalous temperature dependences indicate that the film inhomogeneous phase is stabilized by a repulsive interaction between conducting regions.
Merithew
RD
Department of Physics, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, Illinois 61801-3080, USA.
Weissman
MB
Hess
FM
Spradling
P
Nowak
ER
O'Donnell
J
Eckstein
JN
Tokura
Y
Tomioka
Y