Structure of Gd, Dy, and Er at Low Temperatures

The crystal structures of gadolinium, dysprosium, and erbium metals have been determined over a wide temperature range. The metals are hexagonal close packed and the a₀ unit axis contracts nearly linearly with decreasing temperature, whereas the c₀ unit axis exhibits an abnormal expansion with decreasing temperature below magnetic transformations of the metals. The c₀ behavior is believed to be associated with the magnetic properties of the metals.