  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.
