Investigations on Magnetization and Electron Magnetic Resonance Properties of Nd0.65Ca0.35Mn1–xZnxO3(x = 0, 0.1, 0.3) Nanomanganite

Resumo

Zinc substitution effects on the magnetic ordering of nanosized Nd_0.65Ca_0.35MnO₃ particles prepared by sol–gel method have been investigated by electron magnetic resonance (EMR) technique complimented by magnetization measurements. Bulk Nd_0.65Ca_0.35 MnO₃ exhibits a charge ordering transition at 240 K and an antiferromagnetic transition at 150 K followed by a transition to a ferromagnetic (FM) phase below 50 K. In contrast, the nano Nd_0.65Ca_0.35MnO₃ exhibits only a single transition from paramagnetic to ferromagnetic phase at 102 K which supports the general phenomenon of vanishing phase complexities in nano materials. In this paper, we discuss the effect of 10% and 30% zinc doping on the nano sized Nd_0.65Ca_0.35Mn_1–x Zn_xO₃. Magnetization and EMR studies confirm the existence of ferromagnetism in all the samples which weakens with increasing doping of zinc. Though magnetization measurements do not show the charge order fluctuations and short range antiferromagnetic (AFM) order in the zinc-doped samples, EMR measurements evidence it. Electron magnetic resonance line width increases with zinc doping over a wide range of temperature due to the destruction of motional narrowing.