ESR Study of the Quasi One-Dimensional Cuprate (Ca1-xYx)0.82CuO2

An electron spin resonance (ESR) study has been performed on polycrystalline samples of the quasi one-dimensional cuprate(Ca1-x Y x )0.82 CuO2with 0 ≤ x ≤ 0.435, in which the formal Cu valence varies from +2.36 to +2.00. The samples with 0 ≤x ≤ 0.20 exhibit broad peaks at around 30 K in their DC magnetic susceptibility, while the samples with 0.20 ≤ x ≤ 0.435 show an antiferromagnetic transition below 29 K. We have found that the magnetic behavior of the compounds with 0 ≤ x ≤ 0.20 is accurately described by a contribution from alternating Heisenberg chains (ACH), and a Curie-Weiss (CW) component. After subtracting the CW contribution, the compounds show typical one-dimensional behavior with spin symmetric exchange interactions. Most of the doped hole carriers appear to be localized and dilute the long-range spin correlations along the chain.