Speaker
Mr
Dongyi Zhou
(School of Materials Sci. & Eng. UNSW)
Description
Epitaxial spinel FeV2O4 (FVO) films of ~80 nm thickness were grown on (001) SrTiO3 (STO(001)) substrates by pulsed laser deposition (PLD) technique. By using in-situ RHEED, we find that FVO grows in an island growth mode with a spot-like RHEED pattern observed. Both the X-ray diffraction (XRD) and transmission electron microscopy (TEM) analysis showed that the FVO film have a single-phase spinel structure and is epitaxially cubic on cubic grown on STO(001) substrate. With a 7% lattice mismatch between bulk FVO and STO, Moire fringes along the interface were observed from the film cross-section TEM images, which indicates that the FVO/STO film have a semicoherent-type interface. The NT1 (~120 K) and NT2 (~45 K) were observed in the magnetization-temperature measurement via superconducting quantum interference device (SQUID). The X-ray magnetic circular dichroism (XMCD) and X-ray absorption spectroscopy (XAS) analysis confirmed that the valance status of the Fe and V ions of the spinel oxide FVO film are divalent and trivalent, respectively, as well as the antiparallel arrangement of the Fe and V spins below the NT1 (~120K).
Primary author
Mr
Dongyi Zhou
(School of Materials Sci. & Eng. UNSW)
Co-authors
Prof.
Nagarajan Valanoor
(School of Materials Sci. & Eng. UNSW)
Dr
Qing He
(Department of Materials Science and Engineering, National Chiao Tung University)
Ms
Yanyu Zhou
(School of Materials Sci. & Eng. UNSW)
Prof.
Ying-Hao Chu
(Department of Materials Science and Engineering, National Chiao Tung University)