The low temperature specific heat of Lu-Cu-Y metallic glasses

The specific heat of a series of amorphous metallic alloys of the form Lu_xCu_0.37Y_0.63-x (x = 0, 0.1, 0.3 and 0.4) has been measured between 2 and 50 K, primarily in order to be able to determine the non-magnetic contributions of the specific heat in magnetic RE-Cu-Y amorphous alloys. The data at low temperature fit the simple form C_p = γT + βT³ from which values of γ and θ_D(0) have been determined. Consideration is given to the error that arises if Y is used rather than Lu or La in forming non-magnetic rare earth intermetallics for purposes of determining the non-magnetic contributions to the specific heat of magnetic samples. A simple procedure is described that allows a useful improvement in accuracy in estimating non-magnetic contributions below 20 K if Y is used. The method may also be useful if only a restricted range of compositions using Lu is possible.