Electron Spin Resonance of Cr⁵⁺ in Phenacite (Be₂SiO₄) Single Crystals

Abstract

Electron spin resonance in synthetic phenacite (Be₂SiO₄) single crystals doped with Cr₂O₃ is observed at about 77 K and 4.2 K at 9.5 GHz with g_z=1.9929±0.008, g_x=1.9505±0.0005 and g_y=1.9581±0.0004 and the hyperfine coupling constant A for ⁵³Cr=25.2±0.2 gauss. The ESR signal is enhanced considerably by X-ray irradiation (35 kV, 18 mA, 8 hr). It is proved that this spectrum is attributed to Cr⁵⁺ ion located either at the Be or at the Si sites.