Large Magnetic-Field-Induced Strains in Sintered Chromium Tellurides

TL;DR

This study reports large magnetic-field-induced strains in sintered chromium tellurides Cr3Te4 and Cr2Te3, with volume changes exceeding 1000 ppm at room temperature, surpassing previous magnetostriction values in Cr-based materials.

Contribution

It demonstrates unprecedented large volume magnetostriction in Cr tellurides at room temperature, highlighting the role of microstructural effects and magnetic ordering in strain enhancement.

Findings

Cr3Te4 shows >1000 ppm volume increase at room temperature under 9 T.

Cr2Te3 exhibits 680 ppm volume change at 200 K under 9 T.

Large strains are linked to magnetic ordering and microstructural effects.

Abstract

Sintered samples of Cr3Te4 and Cr2Te3 are found to show large strains accompanied by large volume changes under a magnetic field. In Cr3Te4, volume increases of deltaV/V = 500-1170 ppm by applying a magnetic field of 9 T are observed over the entire temperature range below 350 K. At room temperature, the deltaV/V value exceeds 1000 ppm, which is considerably larger than the maximum values reported for Cr-based magnets thus far and is comparable to the room-temperature value of forced-volume magnetostriction in invar alloys. Cr2Te3 show a large deltaV/V of 680 ppm when applying a magnetic field of 9 T at 200 K. Both samples display particularly large volume increases around the Curie temperature, where they also show negative thermal expansion due to microstructural effects, suggesting that the cooperation between anisotropic lattice deformation associated with the magnetic ordering and microstructural effects is essential for the manifestation of the large magnetic-field-induced volume changes.