Magnetic softening of young's modulus of amorphous Fe90Zr10
Abstract The Young's modulus and the internal friction of amorphous Fe90Zr10 alloy were measured near the Curie temperature using the vibrating reed technique. The modulus shows softening around Tc(= 227 K) and the internal friction undergoes drastic increase in the same temperature range. It is found that both the Young's modulus and the reciprocal of internal friction are inversely proportional to the magnetic susceptibility in the paramagnetic phase.
Impact of Si atoms on the curie temperature of bcc-FeSi alloys
The Curie temperature, Tc, is considered as a second order transition, above which the ferromagnetic coupling between atoms cease to exit. The physical explanation for the transition from a ferromagnetic state to a paramagnetic state is based on localized theory as well as band model. Interestingly, the Tc is for a ferromagnetic element with a defined structure a variable. This report addresses the issue of changing Tc of bcc-Fe imbedded in bcc-FeSi alloy. The Curie temperature of existing bcc- Fe, TC = 1043 K, shifts inside the grain of FeSi alloys to lower values. The silicon atoms have a strong influence on Tc of bcc-Fe. It will be shown that inside the grains of alloys containing bcc-iron, the unit cell with the weakest ferromagnetic exchange integral or Curie temperature, TC, will enforce an immediate alternation of TC of Fe from TC = 1043 K to lower values. The availability of unit cells occupied with the weakest exchange integral is becoming increasingly a key factor for the transition from ferromagnetic state to the paramagnetic state of alloys. Upon the break of exchange integral of unit cell with the weakest exchange integral, a chain reaction will be triggered which eliminate the ferromagnetic coupling of complete atoms. The details of this process are explained more extensively in this report. For better understanding, a study on FeSi alloys as well as Fe alloys with a distribution of interatomic Fe-Fe distances were carried out.
Field-cooling anisotropy energy in Fe-Zr amorphous alloy
Abstract Iron-rich Fe-Zr amorphous alloys seem to be mictomagnetic. The field-induced anisotropy energy of the 8.6 at% Zr alloy at 4.2 K was estimated to be 3.4 × 105 emu/cm-3 from the magnetization curves after cooling in zero field and 100 kOe.