[17p-F202-1~12] 9.5 New functional materials and new phenomena

▼ [17p-F202-11] Size Dependent Paramagnetic Weak Ferromagnetic Transition in Oxygen Deficient La2CuO4 Nanoparticles

〇(DC)Faisal Budiman¹, Kotooka Takumi¹, Yoichi Horibe¹, Hirofumi Tanaka¹ (1.Kyutech)

Keywords:nanoparticles, La2CuO4-y, magnetic property

La2CuO4 (LCO) is a perovskite oxide material and has been used for wide applications such as gas sensing, photocatalytic, memory resistive and it is also based compound of superconductor material. The interesting characteristic of LCO is the existence of lattice instability associated with the rotation of Cu-O octahedron in the structure, allowing the LCO to have several phase transitions, depending on temperature, pressure and also dopant. By varying these conditions, the property of LCO can be controlled. Previously, we have succeeded to fabricate the controlled size of undoped LCO nanoparticles (NPs) by sol-gel method. In the present work, we reported: (1) the fabrication of La2CuO4-y NPs by heat treatment in non-oxidizing environment and (2) investigation of its electric and magnetic properties. XRD profiles reveal that the fabricated LCO4-y has tetragonal structure and the NPs has spherical structure with particle size ~ 70 nm. Temperature dependent magnetic property measurement by SQUID magnetometer shows that both paramagnetic and weak ferromagnetic appeared in the sample, at 5 K and 100 K respectively. It is expected that oxygen vacancies created in the sample causing electron to be trapped, which furthermore induce ferromagnetism in the sample.