Low-frequency mechanical relaxation in CoO crystals

Internal friction Q ⁻¹ was studied in nominally pure and Li-doped CoO crystals at frequencies of about a few Hz in the temperature range from −180 to 20°C. Doping Co crystals with Li results in a new relaxation maximum of Q ⁻¹ at −115°C at a frequency of 3 Hz. The occurrence of this maximum is related to the reorientation of the Co³⁺-Li¹⁺ elastic dipole under external stress.