Identification of thin plates seen in R5(SixGe1−x)4 alloys, where R is Gd, Tb, Dy, and Er

R5(SixGe1−x)4 alloys, where R is Tb, Dy, and Er, have been examined. Their microstructures consisted of large grains with thin plates of a second phase. Energy dispersive spectrometry of the plates revealed a rare earth rich composition. It is proposed that the plates are R5(SixGe1−x)3 compounds, similar to results seen in Gd5(SixGe1−x)4.