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

Conference Paper

Keeble2, Zainab I. Booq1, David J. . 2009

• Publication Work Type: Orul
• Conference Name: 51- The international conference for Nanotechnology Industries
• Conference Location: 51- The international conference for Nanotechnology Industries
• Conference Date: Monday, May 4, 2009
• Sponsoring Organization: King Abdullah institute for nanotechnology in king saud University (KAIN)

Publication Abstract

One of the nanomaterials shapes is the compound from nanomaterials called nanocomposit which produce from distribution the nanomaterials, as the point defects, in any materials to get the best properties for these materials.
The Electron Paramagnetic Resonance (EPR) study of the iron ions are very important where these paramagnetic centres show several desired properties when doped in the host STO (SrTiO3) crystal. It leads to highly disordered local states, higly conductivity, change the STO from simconductor to conductor, ferromagnetic, and ferroelectric transition at local symmetry low. This sample can be used in detectors, receivers, transistor, thin film and Non-Volatile Ferroelectric Random-Access Memories (NVFRAMs).
            This study present 9 GHz band EPR of ions in the monodomain SrTiO3 (STO) crystals at 80 K and magnetic field up to 2T. This research considers both experimental and theoretical studies of EPR of nanomaterials ions in STO crystals. It includes analysis of the structure of the phase transition; spin Hamiltonian parameters, energy levels, the local structure of the position of the nanomaterials (). The special EPR simulation programme written to simulate the experimental results and there is new mathematical model to determine the position to these centres.  The position for the paramagnetic ions moves toward the vacancy by 11 pm with contraction 10.55 %.
            AT 80 K the structure of the phase transition is tetragonal-orthorambic in the low magnetic field (300 mT) but in high filed (1300mT-1700 mT) the phase structure is tetragonal, so the new region of short-range order found of the Fe3+-Vo ions in STO crystals. There are five new lines discovered in high magnetic field and had a transition between the energy levels are -1/2 ↔ +1/2, -3/2 ↔ -1/2. The ratio between the rotation angles of orthorhombic angle ǿand tetragonal angle ø is
                              Ø=1.5ǿ
Keywords: monodomain, phase transition, orthorambic, tetragonal, rotation-angle.