arXiv subjects

Md Ezaz Hasan Khan

Publications and source records attributed to Md Ezaz Hasan Khan.

2 recordsLinked to original sources

arXiv2026

Controlling Quantum Materials by Growth: Thermodynamics, Kinetics, and Defect Engineering in Transition Metal Dichalcogenides

Transition metal dichalcogenides exhibit a wide range of semiconducting, metallic, correlated, and topological electronic states that arise from strong coupling between lattice structure, dimensionality, and electronic degrees of freedom. In these materials, crystal growth is not merely a preparative step but a thermodynamic boundary condition that establishes chemical potentials, defect populations, polytype stability, and access to metastable phases. As a result, synthesis determines the structural and defect landscape from which collective electronic behavior emerges. In this Review, we develop a unified thermodynamic and kinetic framework that connects growth conditions to phase stability, defect energetics, and microstructure. We examine how chemical potential constraints define stability windows, how supersaturation and mass-transport regimes govern nucleation and morphology, and how nonequilibrium pathways enable kinetic trapping and polymorph selection. Bulk and thin-film synthesis approaches, including chemical vapor transport, flux growth, physical vapor transport, solvent-assisted crystallization, chemical vapor deposition, and molecular beam epitaxy, are placed within a common thermodynamic and kinetic map to clarify how distinct growth regimes produce characteristic disorder profiles and structural phases. By explicitly linking synthesis variables to charge-density-wave order, superconductivity, band topology, and correlation effects, this Review establishes crystal growth as a central parameter in determining the effective electronic Hamiltonian realized in experiment. This perspective provides a physically grounded framework for improving reproducibility and guiding deterministic control of emergent quantum phases in layered materials.

cond-mat.mtrl-sci↗

arXiv2025

Pressure-Tuned Magnetism and Bandgap Modulation in Layered Fe-Doped CrCl3

We explore the structural, magnetic, vibrational and optical band gap properties under varying pressures. By integrating first-principles calculations with experimental techniques, including Raman spectroscopy, photoluminescence (PL), uniaxial pressure studies (thermal expansion), and magnetization measurements, we unveil the intricate pressure-induced transformations in Fe-doped CrCl3, shedding light on its structural, electronic, and magnetic evolution. At ambient pressure, Raman spectra confirm all expected Raman-active modes, which exhibit blue shifts with increasing pressure. The PL measurements demonstrate an optical bandgap of 1.48 eV at ~0.6 GPa, with a progressive increase in the bandgap under pressure, transitioning slower above 6 GPa due to an isostructural phase transition. Magnetization results under pressure shows two competing magnetic components (FM and AFM) at ambient conditions, where at the lowest temperature and applied field, the FM component dominates. The presence of competing FM and AFM energy scales is confirmed by Grueneisen analysis of the thermal expansion and their uniaxial pressure dependence is determined. The experimental findings agree with theoretical results based on Density functional theory (DFT). In the experiments, we observe a pressure-enhanced ferromagnetic interlayer coupling that is followed by the stabilization of antiferromagnetic ordering, due to weakened direct interlayer interactions. Above 1.2 GPa the FM component of the magnetism is gone in the experimental observations, which is also in good agreement with DFT based theory. The findings reported here underscore the potential of CrCl3 for use in pressure-tunable magnetic and optoelectronic applications, where, e.g., the delicate balance between FM and AFM configurations could have potential for sensor applications.

cond-mat.mtrl-sci↗