ESR and Nonresonant Microwave Absorption of ErBa2Cu3O7-δ and HoBa2Cu3O7-δ Single Crystals

Abstract
ESR measurements were performed for ErBa2Cu3O7-δ and HoBa2Cu3O7-δ single crystals from 77 K to room temperature. The ESR signals of Er2BaCuO5 and Ho2BaCuO5 were observed, and their temperature variations were investigated. A nonresonant microwave absorption was also observed below the superconducting critical temperature of 93 K, and was investigated. The principal values of lower critical field were determined.