ANOMALIES IN THE CATHODOLUMINESCENCE OF THE ANTIFERROMAGNETIC OXIDES NIO AND COO

Cathodoluminescence (CL) of the antiferromagnetic oxides NiO and CoO h as been investigated. Both compounds show luminescence bands in the vi sible and near infrared spectral ranges, tentatively attributed to int ra-ionic transitions. Dependence of the visible CL intensity with temp erature presents anomalies at about half of the Neel temperature, whic h are explained by the existence of magnetic ordering effects. The res ults are briefly compared with previous reports on the CL from YBa2Cu3 O7-x. (C) 1997 Elsevier Science Ltd.