Formation and texture of palladium germanides studied by in situ X-ray diffraction and pole figure measurements

• Solid-state reaction is studied on a Pd film with Ge substrates.
• Pd2Ge grains have an epitaxial texture on both Ge 100 and Ge 111.
• PdGe grains are found to grow with an axiotaxial texture.
• Retarded PdGe formation on Ge111 is related with strong epitaxy of Pd2Ge.

The solid state reaction between 30 nm Pd films and various Ge substrates (Ge(100), Ge(111), polycrystalline Ge and amorphous Ge) was studied by means of in situ X-ray diffraction and in situ sheet resistance measurements. The reported phase sequence of Pd2Ge followed by PdGe was verified on all substrates. The texture of the germanides was analysed by pole figure measurements on samples quenched in the Pd2Ge and in the PdGe phase on both Ge(100) and (111) substrates. We report an epitaxial growth of Pd2Ge on Ge(111) and on Ge(100). The formed PdGe has an axiotaxial alignment on Ge(111). On Ge(100), the axiotaxial texture is observed together with a fibre texture. The higher formation temperature of PdGe on Ge(111) could be related to the epitaxial alignment of the Pd2Ge parent phase on Ge(111).