Magnesium ferrite thin films: role of interface film/substrate on structural, magnetic and electric properties

K. L. SALCEDO RODRÍGUEZ; B. STRAUBE; S.P. HELUANI; G. A. PASQUEVICH; P. ESQUINAZI; C.E. RODRÍGUES TORRES

Congreso; Multifunctional Oxides: Synergy between fundamental science and novel technologies; 2017

In order to fabricate multifunctional electronic devices, researchers have focused on the study of interfacial structures between two materials with distinct symmetry groups and electronic properties. At the interfaces between oxides, electronic systems with unusual electronic properties can be generated. In this work the interface effect between Mg ferrite and single crystalline substrates (MgO or SrTiO3 (STO)) is explored. Mg ferrite (MgFe2O4) thin films were grown by a Fe-O/Mg-O multilayer process using DC magnetron sputtering on MgO (100) and STO (100) substrates. The samples show high values of saturation magnetization and Curie temperatures above room temperature. While in the case of the sample grown on MgO the hysteresis loops indicate the existence of more than one ferrimagnetic component and lower value of remanence to saturation ratio, the deposited one on STO is mono-component and has a rectangular-shape magnetic loop at alltemperatures below 300 K. The difference is attributed to different microstructures due to the misfit strain caused by the different lattice constants between substrates and ferrite. The electric transport and photoconductivity properties have been investigated on both samples indicating the important role of the STO substrate in the generation of photo carriers and on the final properties of the MgFe2O4 thin films.