Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8153103 | Journal of Magnetism and Magnetic Materials | 2018 | 19 Pages |
Abstract
Diluted bulk magnetic alloy semiconductors DyxGe1âx (xâ¯â¤â¯0.02) were prepared by a two-step fabrication procedure and studied experimentally by XRD, EDX and magnetic methods. The polycrystalline materials had the ccp (cubic closed-packed) structure of the host Germanium up to â2â¯at.% of Dysprosium. They exhibited different low-temperature and high-temperature behavior. Low-field dc magnetic susceptibility data showed sharp peaks and irreversibility between zero-field cooled and field-cooled states for xâ¯<â¯0.02. A stable antiferromagnetic phase with temperature of the antiferromagnetic to paramagnetic transition TNâ¯=â¯25â¯K was observed at xâ¯=â¯2â¯at.% of Dysprosium. The solubility range of the binary DyxGe1âx alloy system is limited to â¼2â¯at.% due to the large atomic radius of the solute. The low-temperature magnetic phase is characterized as spin-glass below 2â¯at.%. The magnetic relaxation and non-linear susceptibility Ïnl of Dy0.01Ge0.99 were analyzed, and the spin-glass phase was defined with the critical exponents of the phase transition βâ¯=â¯0.52â¯Â±â¯0.10, γâ¯=â¯2.85â¯Â±â¯0.10 and δâ¯=â¯6.49â¯Â±â¯0.02. From the Curie-Weiss behavior of the susceptibility at high temperatures, we determined an average effective Dy-Dy exchange constant J1â¯=â¯â6.90â¯K and effective magnetic moment per Dy ion µeffâ¯=â¯10.08â¯ÂµB. The rare-earth Dy atoms behave as isolated in Ge matrix at high-temperatures.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Condensed Matter Physics
Authors
K.B. Paul,