| dc.description |
Following X-irradiation, two previously unreported V<sup>2+</sup> spectra of orthorhombic symmetry have been observed at room temperature in magnesium oxide. For the stronger spectrum, the spin-Hamiltonian parameters are: g<sub>z</sub>=1.9779+or-0.0005, g<sub>x</sub>=1.9814+or-0.0005, g<sub>Y</sub>=1.9793+or-0.0005, D=-0.0580+or-0.0001 cm<sup>-1</sup>, E=0.1126+or-0.0001 cm<sup>-1</sup>, A<sub>z</sub>=-(74.6+or-0.1)*10<sup>-4</sup> cm<sup>-1</sup>, A<sub>x</sub>=-(73.4+or-0.2)*10<sup>-4</sup> cm<sup>-1</sup> and A<sub>y</sub>=-(73.3+or-0.2)*10<sup>-4</sup> cm<sup>-1</sup>, where Z axis is along an (001) crystal direction, X is along (110) and Y is along (110) and where S=3/2, I=7/2. For the weaker spectrum, D=-0.0560+or-0.0005 cm<sup>-1</sup> and E=0.103+or-0.001 cm<sup>-1</sup>. The spin-Hamiltonian parameters differ markedly from those of the orthorhombic V<sup>2+</sup> spectrum observed by Codling and Henderson (1971) in the same lattice. The centres are compared with the Cr<sup>3+</sup> R and R' centres previously observed in MgO. |
