Nd-Zn (Neodymium-Zinc)

The Nd-Zn phase diagram in [Massalski2] was redrawn from [1972Mas].

Recently, this system was thermodynamically assessed by [2008Li], [2008Qi], and [2009Liu] independently. These assessments used the same experimental phase boundary data of [1972Mas] as the basis of their thermodynamic models. Accordingly the calculated phase diagrams were very similar except handling of the NdZn₁₁-NdZn₁₂ phase. According to [1972Mas], NdZn₁₂ is the high-temperature modification of NdZn₁₁, which has a solid solubility range of approximately 1 at.%. [2008Li] and [2009Liu] assumed only NdZn₁₁ exists as a line compound, whereas [2008Qi] assumed that NdZn₁₁ undergoes a polymorphic transformation at about 550 °C.

Figure 1 shows the Nd-Zn phase diagram taken from [2008Li] except the NdZn₁₁-NdZn₁₂ phase area. In this phase diagram, both NdZn₁₁ and NdZn₁₂ are shown as line compounds, but the peritectoidal formation temperature of NdZn₁₁ and the eutectoidal decomposition temperature of NdZn₁₂ are taken from [1972Mas]. Although this seems to be the most natural explanation of the existing experimental data, further confirmation is required.

Fig. 1

Nd-Zn phase diagram