Unique magnetism and structural transformation in rare earth dialumindes

Rare earth metallic alloys play a critical yet often obscure role in numerous technological applications, including but not limited to sensors, actuators, permanent magnets, and rechargeable batteries; therefore, understanding their fundamental properties is of utmost importance. We study structural behavior, specific heat, and magnetism of various binary and pseudobinary rare earth dialumindes by means of temperature-dependent x-ray powder diffraction, heat capacity and magnetization measurements, and first principles calculations. Here, we focus on our recent understanding of low temperature magnetism, and crystal structure of DyAl$_{\mathrm{2}}$, TbAl$_{\mathrm{2}}$, PrAl$_{\mathrm{2}}$, ErAl$_{\mathrm{2}}$, and discuss magnetic and structural instabilities in the pseudobinary PrAl$_{\mathrm{2}}$ -- ErAl$_{\mathrm{2}}$ system [1]. Unique among other mixed heavy lanthanide dialumindes, the substitution of Er in Pr$_{\mathrm{1-x}}$Er$_{\mathrm{x}}$Al$_{\mathrm{2}}$ results in unusual ferrimagnetic behavior, and the ferrimagnetic interactions become strongest around x $=$ 0.25. [1] A. K. Pathak et al, Phys. Rev. Lett. \textbf{110}, 186405 (2013), Phys. Rev. B \textbf{89}, 224411 (2014).