H-T Phase Diagram of Magnetic Semiconductor Thin Films - Experiment

We used the irreversibilities between the field cooled and zero field cooled dc magnetization to determine the field and composition dependence of the spin-glass freezing temperature in CdCr$\text{}_{2}$Se$\text{}_{4}$ : In (REE) and CdCr$\text{}_{2-2x}$In$\text{}_{2x}$Se$\text{}_{4}$ (0.15 ≤ x ≤ 0.35) (SG) thin films. The H-T phase diagram of samples with REE has two instability lines: the Gabay-Toulouse-type (G-T) and the De Almeida-Thouless-type (A-T) while samples in SG state are characterized by the A-T line. The A-T line of thin films was used for calculation the normalised internal magnetic field h$\text{}_{m}$ of infinite spin clusters with long range ordering.