MAGNETIC-FIELD-INDUCED SPATIAL SPIN REORI ENTATION IN DYSPROSIUM ORTHOFERRITE

It has been revealed that a magnetic field H parallel-to b applied dys prosium orthoferrite induces at low temperature T less-than-or-equal-t o 5.5 K spatial spin reorientation GAMMA1 --> GAMMA1234 --> GAMMA4. Th e transition from the antiferromagnetic state GAMMA1 to the state GAMM A1234 with spatial orientation of ferro- and antiferromagnctic vectors is a second-order phase transition and that from the state GAMMA1234 to the weak ferromagnetic one GAMMA4 is a first-order transition.