tailieunhanh - Structure and Magnetic Properties of REMnO3 System

In this study, the perovskite manganites REMnO3 (with RE = La, Nd, Pr) were prepared by a solid-state reaction. The structure and magnetic properties of these samples are reported. The crystal structure of the samples is cubic with LaMnO3 and is orthorhombic with NdMnO3 and PrMnO3 samples. | VNU Journal of Science: Mathematics – Physics, Vol. 32, No. 4 (2016) 6-11 Structure and Magnetic Properties of REMnO3 System Nguyen Thi My Duc1, 2,*, Nguyen Thi Khanh Van1, Makio Kurisu4, Kensuke Konishi4, Phan Manh Huong3, Ngo Thu Huong1 1 Faculty of Physics, VNU University of Science, 334 Nguyen Trai, Hanoi, Vietnam 2 Faculty of Physics, Danang University of Education 3 Department of Physics, University of South Florida, USA 4 Department of Physics, Ehime University, Japan Received 20 October 2016 Revised 16 November 2016; Accepted 28 December 2016 Abstract: In this study, the perovskite manganites REMnO3 (with RE = La, Nd, Pr) were prepared by a solid-state reaction. The structure and magnetic properties of these samples are reported. The crystal structure of the samples is cubic with LaMnO 3 and is orthorhombic with NdMnO3 and PrMnO3 samples. The surface of LaMnO3 sample is dense and quite tight, while the surface of two samples PrMnO3 and NdMnO3 are more porous than LaMnO3 sample surface. The temperature and magnetic field dependent of the magnetizations for all the samples were measured. All the samples are paramagnetic. The maximum value of magnetizations at magnetic field H = 12 kOe for the samples LaMnO3, PrMnO3 and NdMnO3 are (emu/g), (emu/g) and (emu/g), respectively. It shows that the Mmax of LaMnO3 is greater than the Mmax for PrMnO3 and NdMnO3 samples. The results showed the existence of both ferromagnetic and antiferromagnetic phase in all the samples. The Curie temperature, Weiss temperature and Curie constant are ditermined. A comparision of the magnetic property in our samples with the other one is discussed in this paper. Keywords: Magnetic material, REMnO3, perovskite. 1. Introduction Perovskite structural was discovered by Gustav Rose in CaTiO3 material. Today, this term “perovskite” is used for materials with a general chemical formula ABO3, where A is the cation 1, 2 or 3 valence such as Na1+, K1+, Sr2+, Ba2+., B is the