Thermopower method for chemical composition and inhomogeneity measurements in amorphous Ni-P samples

Thermopower measurements around room temperature are carried out as a function of phosphorous content on Ni100−xPx (x = 10 to 23) amorphous alloys prepared by electroless, electroplating, and rapid quenching methods. It is found that the thermopower increases monotonically with P content from negative to positive values, changing sign at about 15 at% of P. A concentration change of about 1 at% P corresponds to (0.5 ± 0.1) μV/K change in thermopower. A method is given, based on a simple thermoelectric probe, to check the in-plane chemical homogeneity of the samples prepared by different techniques. The rapid quenched ribbons are found to be homogeneous, on the other hand inhomogeneities are found in the electroless and electroplated samples depending on the experimental circumstances.