1. Anomalous effects of Sc substitution and processing on magnetism and structure of (Gd1−xScx)5Ge4
- Author
-
Vitalij K. Pecharsky, Volodymyr Smetana, Yaroslav Mudryk, Anja-Verena Mudring, and Jun Liu
- Subjects
010302 applied physics ,Phase transition ,Materials science ,Condensed matter physics ,Magnetism ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Electronic, Optical and Magnetic Materials ,Magnetic field ,Paramagnetism ,Magnetization ,Ferromagnetism ,0103 physical sciences ,Antiferromagnetism ,0210 nano-technology ,Néel temperature - Abstract
The kinetic arrest observed in the parent Gd5Ge4 gradually vanishes when a small fraction (x = 0.025, 0.05 and 0.10) of Gd is replaced by Sc in (Gd1−xScx)5Ge4, and the magnetic ground state changes from antiferromagnetic (AFM) to ferromagnetic (FM). A first order phase transition coupled with the FM-AFM transition occurs at TC = 41 K for x = 0.05 and at TC = 53 K for x = 0.10 during heating in applied magnetic field of 1 kOe, and the thermal hysteresis is near 10 K. The first-order magnetic transition is coupled with the structural Sm5Ge4-type to Gd5Si4-type transformation. The magnetization measured as a function of applied magnetic field shows sharp metamagnetic-like behavior. At the same time, the AFM to paramagnetic transition in (Gd1−xScx)5Ge4 with x = 0.10, is uncharacteristically broad indicating development of strong short-range AFM correlations above the Neel temperature. Comparison of the magnetization data of bulk, powdered, and metal-varnish composite samples of (Gd0.95Sc0.05)5Ge4 shows that mechanical grinding and fabrication of a composite have little effect on the temperature of the first-order transformation, but short-range ordering and AFM/FM ratio below TC are surprisingly strongly affected.
- Published
- 2019