On the Crystal Distortion in Several Spinel Systems(Physics)
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The composition and temperature dependence of cooperative Jahn-Teller distortions have been studied in the spinel mixtures CuFe_<2-2x>Zn_xTi_xO_4. CuFe_<2-2x>Zn_xGe_xO_4, and CuFe_<2-2x>Ga_<2x>O_4 which contain Cu^<2+>-ions in B-sites In the former two cases the tetragonal distortion rapidly disappears with the substitution of a small amount of Fe^<3+> by Zn^<2+>Ti^<4+> or Zn^<2+>Ge^<4+>. Electrostatie potentials in these systems have been calculated from the measured values of the u-parameter and the cause of the non-distortion has been investigated on the basis of the intrinsic energy of the crystal. The effective Bohr magneton number of Cu^<2+>-ions of the spinel CuFe_<0.8>Ga_<1.2>O_4 deduced from the 1/x-T curve takes a value close to the calculated one corresponding to the "spin-only" state of Cu^<2+>ions even above the cubic-to-tetragonal transformation temperature.
- Science reports of the Research Institutes, Tohoku University. Ser. A, Physics, chemistry and metallurgy
Science reports of the Research Institutes, Tohoku University. Ser. A, Physics, chemistry and metallurgy 26 362-362, 1976