Electron paramagnetic resonance of Fe3+ in gallium borate: Superposition model analysis

A series of high quality FexGa1−xBO3 single crystals with 0 ≤ x ≤ 1 was prepared and studied by electron magnetic resonance in the temperature range from 4 to 290 K. At low x, only the electron paramagnetic resonance (EPR) of diluted Fe3+ ions is present. The EPR spectra for different orientations of the magnetizing field have been computer simulated. With a conventional spin Hamiltonian including the Zeeman and fine-structure terms, two different sets of best-fit parameters have been found. This ambiguity has been resolved on the basis of the general spin Hamiltonian with parameters determined from the crystallographic data using the Newman superposition model. A detailed fitting to the experimental EPR spectra assuming statistical distributions of Fe3+ ligand coordinates has revealed the existence of a certain degree of local disorder in FexGa1−xBO3 single crystals

Fe-x Ga-(1−x)BO-3 single crystals: synthesis and characterization

A series of Fe-x Ga-(1-x)BO-3 single crystals in the concentration range 0<=x<=1 has been synthesized by solution in the melt method. In order to determine optimal crystallization regimes, two settings have been worked out and applied in the present study: the first one, for precise differential thermal analysis and the second one, for the probe method. X-ray fluorescence and X-ray diffraction analysis have allowed accurate determination of iron contents and lattice parameters for synthesized crystals with different x. Computer-assisted EPR studies of Fe+(3+) have revealed a high perfection of the crystals: low degree of disorder and the absence of twinning