Electric Field Effects on the Spectrum of Chromium in Strontium Titanate

Abstract

An electric field of 4 kV/cm applied to a crystal of SrTi${\mathrm{O}}_3$:${\mathrm{Cr}}^{3+}$ at 4.2°K shifts the chromium $R$ lines by about 2 ${\mathrm{cm}}^{-1\mathrm{}}$ and increases their integrated intensity by 8%. The intensity increase is attributed to an induced electric dipole transition made possible when the ${\mathrm{Cr}}^{3+}$ ion is displaced from the center of symmetry by the applied electric field.