Abstract
Polarized neutron-diffraction experiments have been performed in search of the orbital magnetic moments recently predicted in a theory for the cuprate metals. Both La{sub 2{minus}x}Sr{sub x}CuO{sub 4} [LSCO(x)] and YBa{sub 2}Cu{sub 3}O{sub 6+x} [YBCO(x)] compounds were investigated. No definitive evidence for the existence of such a three-dimensionally ordered moment was found in any of these samples within experimental uncertainty, which was as low as 0.01{mu}{sub B}. We have also investigated the possibility that a magnetic rod exists parallel to the {ital c} axis in the case of two- or quasi-two-dimensional ordering in the (a,b) plane and have set an upper limit for the total moment to be 0.1{mu}{sub B} in LSCO (x=0.1). {copyright} {ital 1999} {ital The American Physical Society}