Effect of substrate temperature on structure, cationic distribution and electrical properties of MnCo_0.2Ni_0.1Mg_0.6Al_1.1O₄ thin films

MnCo_0.2Ni_0.1Mg_0.6Al_1.1O₄ thin films were prepared on a Si/SiO₂ substrate by the radio frequency sputtering method at various substrate temperatures. The structural properties was characterized and the results indicated substrate temperature had a significant impact on preferred crystal orientations, surface morphology and cation distribution of the films. Investigation of the electrical properties revealed that all the films exhibited negative temperature coefficient character and their thermal constants varied from 2230 to 3974 K as the substrate temperature increased to 250 °C; this value was highly dependent on the occurrence of the (400) spinel orient peak and the occupancy of Mg²⁺ at octahedral sites.