Coexistence of para and ferromagnetic phases of Fe~(3+) in undoped CdZnTe (Zn?4) crystals

摘要

The signatures of the coexistence of para and ferromagnetic phases for the Fe~(3+) charge state of iron have been identified in the low temperature electron spin resonance (ESR) spectra in undoped CdZnTe (Zn～4) crystals and independently verified by superconducting quantum interference device (SQUID) and AC susceptibility measurements. In the paramagnetic phase the inverse of AC susceptibility follows the CurieWeiss law. In the ferromagnetic phase the thermal evolution of magnetization follows the well-known Bloch T32 law. This is further supported by the appearance of hysteresis in the SQUID measurements at 2 K below TC which is expected to lie in between 2 and 2.5 K.