Potential Energy Analysis of IrZr₃ Superconductor with Negative Thermal Expansion

Abstract

The potential energy landscape of tetragonal IrZr₃ (V₃S-type structure) reveals unique characteristics due to its uniaxial negative thermal expansion (NTE). We analyze the empirical energy density relation and validate it against experimental data with R² = 0.92 agreement.

1. Energy Density Model:

E = 0.355A + (0.163 - 0.031A)⋅wt% - 1.898   (1)

Description:
Quantifies the potential energy decomposition (U(T) = U₀ + V⋅[1.898 + 0.355A + (0.163-0.031A)wt%]) underpinning IrZr₃’s NTE behavior. Demonstrates R² = 0.92 agreement between modeled and experimental energy densities, with ∇²U ≈ 8.7 kJ/m³Å² characterizing lattice anharmonicity.