Authors: Daly Paul; K.N. Anuradha; S.V. Bhat
Addresses: Department of Physics, RNS Institute of Technology, Bangalore, 560098, India ' Department of Physics, Dr. Ambedkar Institute of Technology, Bangalore, 560056, India ' Department of Physics, Indian Institute of Science, Bangalore, 560012, India
Abstract: In this paper, we report the synthesis and magnetic properties of Nd0.65Ca0.35Mn0.9Zn0.1O3 manganite. Bulk (NZOB) and nanoparticles (NZON) of hole-doped Nd0.65Ca0.35Mn0.9Zn0.1O3 were prepared by sol gel method. These particles were characterised by XRD, TEM and EDAX. Magnetisation measurements were carried out in temperature range 10 K ≤ T ≤ 300 K by a SQUID magnetometer. The parent bulk Nd0.65Ca0.35MnO3 (NCMO) manganite exhibits charge order (CO) around the temperature 210 K followed by an antiferromagnetic (AFM) transition at the Neel temperature (TN = 120 K). With the doping of nonmagnetic Zn2+ cation, the valency balance is maintained by the creation of Mn4+ ions, which leads to ferromagnetism owing to the double exchange interaction between Mn3+ and Mn4+. Magnetisation measurements show that the ferromagnetic component enhances in nanoparticles (NZON) as compared to its bulk counterpart at low temperature, along with some amount of residual antiferromagnetism owing to the uncompensated surface spins. Further the temperature dependence of magnetisation (M*T vs. T) shows the melting of CO in both the samples. The ferromagnetic transition temperature (Tc) is found to be higher (~53 K) in nanosample (size about 20 nm) when compared with its bulk counterpart (~41 K).
Keywords: Zn doped Nd0.65Ca0.35MnO3; nanoparticles; double exchange charge order; ferromagnetism; magnetisation; manganites; perovskite; colossal magnetoresistance; CMR; antiferromagnetism.
International Journal of Nanotechnology, 2017 Vol.14 No.9/10/11, pp.885 - 892
Received: 08 May 2021
Accepted: 12 May 2021
Published online: 25 Jun 2017 *