Structural and magnetic properties of Mn3O4 films grown on MgO(0 0 1) substrates by plasma-assisted MBE

• Published in: Journal of magnetism and magnetic materials 2000-05, Vol.213 (3), p.321-325
• Main Authors: Guo, L.W, Peng, D.L, Makino, H, Inaba, K, Ko, H.J, Sumiyama, K, Yao, T
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Curie temperature; Exact sciences and technology; Magnetic properties and materials; Magnetic properties of monolayers and thin films; Magnetic properties of surface, thin films and multilayers; Magnetization; MBE; Oxides; Physics; Thin films
• ISSN: 0304-8853
• DOI: 10.1016/S0304-8853(00)00008-1

Mn3O4 thin films with distorted spinel structure are grown on MgO(001) substrates by plasma-assisted molecular beam epitaxy (MBE). The films are (001) oriented and the lattice parameters are a=b≈5.72Å, and c≈9.5Å, with c/a=1.66 slightly larger than the ratio of 1.64 for bulk single-crystal samples, if a body-center tetragonal unit cell is adopted for Mn3O4. It is found that the Curie temperature TCF of the Mn3O4 film is 46K higher than (TCB=42K) for bulk single-crystal samples. The spontaneous magnetization reaches 1.73μB/molecule which is in between the reported results of 1.56μB/molecule for polycrystalline and 1.85μB/molecule for single-crystal sample. The temperature dependence of the inverse magnetic susceptibility in the paramagnetic range agrees well with the Curie–Weiss formula. The induced effective magnetic moment for Mn ion is about 3.59μB, which is small compared with the 5.24μB/magnetic atom calculated based on electronic spins only.