Heat conduction and magnetic phase behavior in electron-doped Ca1-xLaxMnO3 (0≤x≤0.2) -: art. no. 100404

Measurements of thermal conductivity (kappa) vs temperature are reported for a series of Ca1-xLaxMnO3(0less than or equal toxless than or equal to0.2) specimens. For the undoped (x=0), G-type antiferromagnetic compound a large enhancement of kappa below the Neel temperature (T(N)similar to125 K) indicates a strong coupling of heat-carrying phonons to the spin system. This enhancement exhibits a nonmonotonic behavior with increasing x and correlates remarkably well with the small ferromagnetic component of the magnetization reported previously [Neumeier and Cohn, Phys. Rev. B 61 14319 (2000)]. Magnetoelastic polaron formation appears to underly the behavior of kappa and the magnetization at xless than or equal to0.02.