Electron Paramagnetic Resonance Studies of Iron ions (Fe3+ - VO) as nanomaterials in Strontium Titanate Oxide (SrTiO3) Crystals at 80K

Abstract

Abstract This work presents the structure of the phase transition of Fe3+ - V0 ions in SrTiO3 Crystals using Bruker EMX EPR spectrometer with an X-band (9.1–9.9 GHz) under nitrogen gas preserved. In the low magnetic field (300 mT) the structure is tetragonal (C4v)-orthorambic (C2v) but in high magnetic field (800 mT-1700 mT), it becomes tetragonal (C2v) only.The spectra exhibit sixteen lines originating from defect centers laying on three original direction equivalent to < 100>, others tilted a way from these directions by orthorambic angle\(\stackrel{-}{\varvec{\varnothing }}\)=±0.8, in addition to a tetragonal angle \(\varvec{\varnothing }\)=±1.2. The observed transition lines occur between the energy levels − 5/2↔-3/2,-5/2↔-1/2, -1/2↔+1/2, -3/2 ↔-1/2. The spin Hamiltonian parameters are investigated by mathematical model (SM) and simulation programme written in this research. The position of defects Fe3+ - V0 are determined, showing that the paramagnetic Fe3+ ions moves toward the vacancy by 11 pm with a contraction of 10.55%.