Аннотация:An x-ray diffraction study of the ferromagnetic compound CrTe with the NiAs-type structure was
carried out at temperatures in the region of the magnetic transition point. The results obtained
indicated that the magnetic ordering, which appeared when the temperature was lowered, was accompanied by an anomalous increase of the lattice parameter a. The ordering did not have a perceptible effect on the temperature dependence of the lattice parameter c. Near the magnetic transition temperature, the thermal expansion coefficient a-1
8a/8T was -65 x 10-6
deg-1
at temperatures
T < Tc, whereas a-1
aa/8T Rl c-1
8c/8T = +28 x 10-6
deg-1
at temperatures T > Tc· The absence of
an appreciable spontaneous magnetostriction along the c axis was attributed to the existence of two
competing and different exchange interactions. The observed anomaly in a(T) was ascribed to a
strong dependence of the dominant positive exchange interaction in the basal plane on the interatomic spacing.