Dissipative heat and exchange dispersion on metastability of Gd5Si4

Abstract The response of the magnetic and crystal structure of Gd 5 Si 4 to both ‘isothermal’ and ‘thermo-mechanical’ process is investigated by the dispersion exchange fluctuation, which can be the cause of the compound's metastability. The X-ray diffraction DTA, SEM and magnetization at room temperature are measured to explore the effect of annealing process (latent heat as isothermal) at different annealing temperatures. The discharge heat (exchange heat) by the annealing process, which is manifested by the thermal loop of DTA, is caused by the reduction in the lattice constant as well as in magnetization behavior measured at room temperature with no observable crystal phase transition. The exchange fluctuation (entropy), which is related to the DTA thermal loop, is increased by the sample's heat absorption (discharge heat) in the direction to lower the free energy of the crystal. The crystallographic slip is investigated by the dissipative heat through the high ball milling energy (HBME) to provide the nature and strength of the exchange. It is shown that the DTA thermal loop and SEM-crystallographic slip should be the character of the “exchange heat” (discharge heat) and “heat exchange” (absorption of heat through the wet environment of ball milling).