Investigation of polar and magnetic ordering in transition metal oxide thin film heterostructures

Abstract

Oxides become an important group of quantum materials of interesting fundamentalmany body physics due to the presence of strongly correlated electronic and magneticstates The hunch for developing new devices using the broad functionalities of Oxideshas given the birth of new technical field called Oxide Electronics Over past two decadesresearch in oxide thin fi lms has been boosted due to the invention of new deposition techniques to make ultra thin single crystalline films with novel structure and functionality ofthe material that are inaccessible in it s bulk from with the help of reduced dimensionalityand strain engineering with substrates Designing novel polar and magnetic ordering insome new strain stabilized engineered oxide thin films as well as heterostructures is goingto be the key focus of this thesis with a strong future perspective in quantum technologyand device science A variety of ferroelectric and ferromagnetic transition metal oxides TMO have beenthoroughly explored in this thesis in terms of their thin fi lm growth as well as polar andmagnetic properties Firstly thin fi lm of arti ficial hexagonal phase of perovskite TbMnO3has been grown and stabilized with the imposed strain of the substrate The high ferro electric transition temperature Tc 800 K of this room temperature ferroelectrics hasbeen investigated with temperature dependent Transmission Electron Microscopy Ramanspectroscopy and optical ellipsometry Secondly thin film of monoclinic double perovskiteTb2CoMnO6 has been grown and it s detail dielectric and magnetic properties have beeninvestigated An interesting and novel ferroelectric relaxor glass phase has been observedin this ferromagnetic oxide along with a magneto dielectric coupling 4 at considerablehigh temperature Third and most importantly a 3d 5d electronic system based perovskiteferroelectric magnetic thin film hetero structure of newline newline