Isothermal section of the Al–Dy–Ge ternary system at 673 K

The isothermal section of the phase diagram of the Al–Dy–Ge ternary system at 673 K has been investigated by X-ray powder diffraction and scanning electron microscope equipped with energy dispersive X-ray spectroscopy in backscattered electron imaging modes. The existence of thirteen binary compounds including Dy3Ge4 in the system Dy–Ge has been confirmed. Four ternary compounds, namely AlDyGe, Al3Dy2Ge4, AlDy2Ge3, and AlDy2Ge2 were observed, and five new ternary compounds, i.e., Al0.33DyGe2, AlDy2Ge6, Al2DyGe2, AlDy3Ge3, and Al3−xDy11Ge7+x (x ≤ 0.7), and one pseudo-binary compound Al3−xDyGex were found in this system at 673 K. The maximum solid solubility of Ge in the pseudo-binary compounds Al3−xDyGex is about 7.5 at.% with x = 0.3 at 673 K.

Research highlights
► The isothermal section of the phase diagram of the Al–Dy–Ge ternary system at 673 K has been investigated by X-ray powder diffraction and scanning electron microscope equipped with energy dispersive X-ray spectroscopy in backscattered electron imaging modes.
► Five new ternary compounds, i.e., Al0.33DyGe2, AlDy2Ge6, Al2DyGe2, AlDy3Ge3, and Al3−xDy11Ge7+x (x ≤ 0.7), and one pseudo-binary compound Al3−xDyGex were found in this system at 673 K.
► The maximum solid solubility of Ge in the pseudo-binary compounds Al3−xDyGex is about 7.5 at.% with x = 0.3 at 673 K.