Enhanced Ferromagnetic Insulating State In La[sub 0.85]Ca[sub 0.15]Mn[sub 1−x]Cr[sub x]O[sub 3] (0≤x≤0.1)

Abstract

In order to investigate the ferromagnetic insulating state of La 0.85 Ca 0.15 MnO 3 (LCM) system, Cr has been doped on its Mn site. The x-ray diffraction data indicate that there is no structural change due to Cr doping up to x = 0.1. In La 0.85 Ca 0.15 Mn 1-x Cr x O 3 (LCMC, 0 x 0.1), the Jahn-Teller (JT) distortion is weakened and double exchange (DE) mechanism is stalled. As a result, an increase in resistivity is observed with the increase of Cr doping. Nevertheless, the magnetic couplings are strengthened by Cr doping and the system is derived towards more ferromagnetic (FM) ordering. Metal-insulator (MI) transition of the parent compound (x = 0) is suppressed by doping and ultimately becomes insulating for x = 0.1. It is observed that Cr doping stabilizes the FMI state at low temperatures.