Preparation of epitaxial CaMn7O12 film via sol-gel method and its ferromagnetic properties

CaMn 7 O 12 precursor sol was prepared by using Ca(NO 3 ) 2 ·4H 2 O and Mn(CH 3 COO) 4 ·4H 2 O as the raw materials, acetylacetone (AcAcH) as the chelating agent, and methyl alcohol (MeOH) as the solvent. The CaMn 7 O 12 crystalline film was obtained via dip-coating and annealing treatment on the LaAlO 3 (001) single-crystal substrate. XRD θ -2 θ scan indicated that the as-prepared CaMn 7 O 12 film had strong preferred orientation along the c -axis. In addition, the results of the ω and ϕ scans demonstrated that the film exhibited outstanding out-of-plane and in-plane texture characteristics. The SEM characterization showed that the CaMn 7 O 12 film was dense and free of cracks. The grain size was uniform with an average size of ~180 nm. Vibrating sample magnetometer (VSM) test results indicated the CaMn 7 O 12 film was antiferromagnetic and had a saturation magnetization of 114.2 emu/cm 3 at 50 K.