Challenges in EQA and POCT

Abstract

In this work, α-phase Fe-12 V alloy (at.%) with high total magnetostriction is selected to perform Mössbauer and Vibrating Sample Magnetometer (VSM) measurements to investigate the temperature dependence of atomic clusters and the magnetic properties. The results show that with increasing temperature, the ferromagnetism firstly drops and then slightly increases, and finally decreases severely, which is mainly determined by the variations of the three kinds of atomic clusters (Fe-rich, V-rich and free-Fe) in the alloy. The hyperfine magnetic field, which decreases with temperature, is always dominated by the Fe-rich clusters. The atomic combination of the free-Fe clusters also determines the magnetic properties in the temperature range from room temperature to 600 °C; however, the free-Fe clusters contribution to the hyperfine magnetic fields tends to become zero above 600 °C, whereas that of the V-rich becomes obvious. When the temperature is high enough, the hyperfine magnetic field decreases sharply due to the destruction of the ordered Fe-rich state. VSM was selected to understand the relationship between the magnetic moment and the heating temperature, and the Curie temperature (TC=836.36 °C) of the Fe-12 V alloy was obtained as well. Finally, the formula reflecting the magnetic moment of the α-phase Fe-12 V alloy varying with temperature is also successfully derived.