Giant magnetothermal conductivity and magnetostriction effect in the charge ordered Nd 0.8 Na 0.2 MnO 3 compound

Abstract

We present results on resistivity (ρ), magnetization (M), thermal conductivity (κ), magnetostriction (ΔLL(0)) and specific heat (Cp) of charge-orbital ordered antiferromagnetic Nd0.8Na0.2MnO3 compound. Magnetic field-induced antiferromagnetic/charge-orbital ordered insulating to ferromagnetic metallic transition leads to giant magnetothermal conductivity and magnetostriction effect. The low-temperature irreversibility behavior in ρ, M, κ and ΔLL(0) due to field cycling together with striking similarity among the field and temperature dependence of these parameters manifest the presence of strong and complex spin-charge-lattice coupling in this compound. The giant magnetothermal conductivity is attributed mainly to the suppression of phonon scattering due to the destabilization of spin fluctuations and static/dynamic Jahn-Teller distortion by the application of magnetic field.