Disordered Materials

Disordered systems stand apart due to their lack of long-range atomic order, which often enhances their mechanical, magnetic, and electronic properties. In HEAs, a multi-component, near-equimolar composition creates high configurational entropy, resulting in properties like exceptional strength, corrosion resistance, and thermal stability. This configurational randomness also allows disordered systems to bypass traditional alloying limitations, enabling fine-tuning of properties via compositional adjustments and doping. This power comes with the challenge that, since the basis set is no more periodic, the Bloch’s theorem, one of the corner stone of computational materials science is no more valid. Such tunability has found applications in energy-efficient technologies, including hydrogen evolution reactions and magnetocaloric refrigeration, and advanced devices like spintronic components.

At MAVENs, we focus on advancing the understanding and application of disordered systems, including Heusler alloys (X$_2$YZ) and MXenes (MₙXₙ₋₁) for green energy and advanced technologies. Utilizing density functional theory (DFT) with Plane-wave based supercell methods and Green’s function based CPA methods, the group investigates doping strategies to tune electronic and magnetic properties.

Recent achievements include the development of Ni-Mn-based shape memory alloys with an extended operating temperature range and the enhancement of magnetocaloric effects in Fe-Cr-V-based systems. Our work on Mn$_2$CoAl highlights the group’s proficiency in using computational methods to provide critical insights for experimentalists. By investigating site-selective doping and its effects on properties like (T$_C$) and SGS behavior, the MAVENs group paves the way for designing next-generation materials tailored for specific applications.

MXenes, on the other hand have been used as a good catalyst for hydrogen evolution reaction. Our work has shown that Zr doped Ti$_3$C$_2$ and Ti$_3$CN has a good catalytic properties with $\mathsf{|\Delta G_H|\approx 0.1 eV}$, improving the value in significant amount from pure Ti$_3$C$_2$.