Coexistence of para and ferromagnetic phases of Fe3+ in undoped CdZnTe (Zn∼4%) crystals

The signatures of the coexistence of para and ferromagnetic phases for the Fe3+ 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 Curie-Weiss law. In the ferromagnetic phase the thermal evolution of magnetization follows the well-known Bloch T3/2 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.