ESR and Nonresonant Microwave Absorption of YBa2Cu3O7-δSingle Crystal

Abstract
ESR measurements were performed for a single crystal of YBa2Cu3O7-δover a temperature range from 77 K to room temperature. ESR signals of Y2BaCuO5and CuO were observed and investigated. Nonresonant microwave absorption was observed below the superconducting critical temperature of 93 K and was also investigated. The principal values of lower critical field were determined.