TRANSVERSE SPIN FREEZING IN ANTIFERROMAGNETIC GAMMA-MN90CU10

gamma-Mn90Cu10 is face-centred tetragonal with c/a < 1 and antiferroma gnetic with the antiferromagnetic direction along the c-direction. Low -field (100 Oe) field-cooled (FC) and zero-field cooled (ZFC) magnetic susceptibility measurements on a crystal which is more than 98% one-d omained clearly show spin freezing at 50 K, well below the Neel temper ature of about 465 K. Measurements taken parallel to the antiferromagn etic direction show that the difference between the ZFC and FC suscept ibilities is about half of that taken perpendicular to the antiferroma gnetic direction (along [1 1 0]). (C) 1998 Elsevier Science B.V. All r ights reserved.