Investigation of in-chain spin correlations in YBa 2Cu 3O 6+ x by neutron polarization analysis

Abstract

Spin correlation in Cu–O chains of YBCO are studied. The results were obtained at T=110 K by neutron polarization analysis with 3He filter as analzyer. Experimental data indicate a magnetic peak at k=0.75, which corresponds to the holes concentration in the chain c=0.5. There is another anomaly at k=0.5 ( c=0), which may be connected with the sample inhomogenity and some admixtures of copper oxide. The cross-section in the peak at k=0.75 is 5 mb/sr.