Electron spin resonance study on pure single crystalline sapphire

Abstract Paramagnetic spin is investigated using electron spin resonance technique at room temperature for a pure sapphire, or single crystalline sapphire that is made without any intentional doping. In particular, the spin density of the pure sapphire is compared with that of a commercial available sapphire. Four kinds of signals are detected for commercially available sapphire, all of which have spin density on the order of 1015 cm‐3. It is found that for the pure sapphire, one of them is missing and rest of the three have lower density on the order of 1014 cm‐3 or lower. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)