ESR STUDY OF DEFECTS IN SPIN-GAP MAGNETS

摘要

Impurities in spin-gap systems provide a local destruction of the singlet state, resulting in formation of spin clusters with the local antiferromagnetic order. The ESR measurements enable one to estimate the size of spin clusters and to determine the effective spin of the clusters. The special attention is payed to the impurity induced magnetic ordering on the singlet and disordered background of a spin-gap magnet. A special kind of the microscopic phase separation is observed at this impurity induced ordering.