CRYSTAL-STRUCTURE AND MAGNETIC-INTERACTIONS IN ZRCR2S4

The evaluation of exchange integral intensities J(i) is extended to th e fourth order (i = 1, 2, 3, 4) for the spinel sulphur. We have perfor med EPR and dilatation measurements on a single crystal in the tempera ture range 4.2 K less than or equal to T less than or equal to 300 K. The J(i)-value is compared with that deduced from EPR measurements. Di latation measurement confirms the absence of any tetragonal distortion as found by neutron diffraction. A comparison between results obtaine d on a polycrystal and a single crystal is given.