MAGNETOSTRICTION OF THE SPIN-PEIERLS COMPOUND CUGEO3

The magnetostriction lambda of spin-Peierls compound CuGeO3 was measur ed in magnetic field up to 18 T both above, and below the transition t emperature T-sp = 14.3 K. In uniform phase at T > T-sp lambda in b-c p lane is negative and isotropic, while in dimerized phase at T < T-ap l ambda is positive and anisotropic (lambda(b) > lambda(c)). At low temp eratures lambda increases sharply at transition from dimerized to magn etic phase.