Anomalous Specific Heat of Chromium Oxide (Cr 2 O 3 ) at the Antiferromagnetic Curie Temperature

RECENTLY, some observations have been published of phenomena related to the second-order transition of chromium oxide (Cr 2 O 3 ) at the antiferromagnetic Curie temperature; for example, the change of lattice constants 1 and the anomalous absorption of high-frequency electromagnetic energy 2 . However, so far as I am aware, no measurements of an anomalous specific heat have been published. In the present communication, measurements are presented of C p between 100° and 350° K. and of the magnetic susceptibility χ between 77° and 550° K., which were made on samples of the same preparation of chromium oxide.