Disordered Materials

The Challenge:

Disordered systems can enhance mechanical, magnetic, and electronic properties. In high-entropy alloys (HEAs), multi-component, near-equimolar compositions create high configurational entropy, resulting in exceptional strength, corrosion resistance, and thermal stability. This configurational randomness allows fine-tuning of properties through compositional adjustments and doping.

The computational challenge arises because disordered systems lack periodicity, making Bloch’s theorem invalid. These materials find applications in energy-efficient technologies, including hydrogen evolution reactions and magnetocaloric refrigeration, and in spintronic devices.

Our Approach:

We investigate disordered systems, including Heusler alloys (X₂YZ) and MXenes (Mₙ₊₁Xₙ) for green energy and advanced technologies. We use density functional theory (DFT) with plane-wave based supercell methods and Green’s function based coherent potential approximation (CPA) methods to study doping strategies that tune electronic and magnetic properties.

Recent Achievements:

Our computational work has identified Ni-Mn-based shape memory alloys with extended operating temperature ranges and enhanced magnetocaloric effects in Fe-Cr-V-based systems.

We investigated site-selective doping effects on Curie temperature (Tc) and spin-glass (SGS) behavior in Mn₂CoAl, providing insights for spintronics applications.

For MXenes, we demonstrated that Zr-doped Ti₃C₂ and Ti₃CN exhibit superior catalytic performance for hydrogen evolution reactions with |ΔGₕ| ≈ 0.1 eV, improving upon pure Ti₃C₂ properties.