ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Metallic ferromagnetism and negative Poisson’s ratio in CoNiTe half-heusler alloy: insights from first-principles calculations

N. Bouzakraoui, A. Samih, R. El Fdil, E. Salmani, M. Naziruddin Khan, Z. Fadil, Chaitany Jayprakash Raorane, and Seong-Cheol Kim

Laboratoire de Matière Condensée et Sciences Interdisciplinaires (LaMCScI), URL-CNRST, Faculty of Sciences, Mohammed V University, Rabat, Morocco

E-mail: fadilzakaria604@gmail.com

Received: 16 December 2025  Accepted: 3 February 2026

Abstract:

First-principles calculations based on density functional theory (DFT) were performed to comprehensively investigate the structural, elastic, thermodynamic, electronic, magnetic, and optical properties of the CoNiTe half-Heusler alloy. Structural optimization revealed that the FM-Type-2 configuration, with a lattice parameter of 5.73 Å, is the most energetically favorable phase, characterized by negative formation energy and high cohesive energy. The calculated elastic constants and phonon dispersion curves confirm mechanical and dynamical stability, while a negative Poisson’s ratio demonstrates the auxetic nature of the compound, suggesting potential for advanced functional applications that exploit auxeticity and mechanical tunability. Thermodynamic analysis further supports the thermal stability of CoNiTe at high temperatures. Electronic structure calculations, carried out using the GGA, SCAN, and GGA + U functionals, indicate metallic behavior in both spin channels. The alloy exhibits ferromagnetic ordering with a total magnetic moment of 2.00 µB and a spin polarization of 54% at the Fermi level, underscoring its suitability for spintronic devices. Finally, the optical response shows strong absorption in the ultraviolet (UV) range and pronounced reflectivity in the infrared (IR), indicating that CoNiTe is a promising multifunctional material for UV photonic and infrared detection technologies.

Keywords: Half-Heusler alloy; GGA-PBE; Meta-GGA-SCAN; GGA + U; Optoelectronic applications; Spintronic applications

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-026-04714-8

Chemical Papers 80 (5) 5351–5364 (2026)