Temperature and Magnetic Field Dependence of Crystal Structure of Monoclinic Cr₃Te₄

Cr₃Te₄ crystals are grown by the chemical vapor transport (CVT) method. X-ray diffraction studies show a monoclinic phase with a = 13.9769 , b = 3.93022 Å, c = 6.86188 Å, β = 118.281°, and unit cell volume 331.946 ų at room temperature. Magnetic studies show a paramagnetic-to-ferromagnetic phase transition around 320 K and another to an anti-ferromagnetic phase below 90 K. We studied the evolution of the crystal structure of Cr₃Te₄ with temperature and magnetic field at the National Synchrotron Light Source-II beamline 28-ID-1. Analysis of our data shows that the unit cell volume scales linearly with temperature above the Curie temperature of 320 K and below 90 K but shows non-Debye behavior in the intermediate range. Under increasing temperature, unit cell parameter a shows a positive correlation through the whole temperature range. In the intermediate range, unit cell parameters b and c correlate negatively with increasing temperature from 90 K to 320 K but correlate positively elsewhere. Cell parameter β shows anomalous behavior within the intermediate temperature range. Under a magnetic field sweep at 90, 310, and 320 K, crystal parameters show linear increases with field and there is an absence of hysteresis. Our study provides valuable insights into the structural and magnetic properties of Cr₃​Te₄​, highlighting its potential for magnetocaloric applications.