AlH6 Clathrate Confined within h-BN: Design, Ab Initio Estimates, Synthesis Route and a Quantitative Assessment toward High-Temperature Superconductivity

Abstract

Giustino Travaglini

I propose and analyze a materials architecture in which an aluminium-hydride clathrate (nominal AlH motifs forming a connected network) is mechanically and chemically confined within an inert, high-stiffness hexagonal boron nitride (h-BN) matrix. The confinement is intended to provide “chemical pressure” and kinetic stabilization of a hydrogen-rich network while preserving the light-mass phonon modes of hydrogen that can drive strong electron-phonon coupling. I present (i) an atomistic model and stability considerations; (ii) detailed computational workflows to evaluate electronic structure, phonons, anharmonic renormalization, electron-phonon coupling, and superconducting transition temperature (Tc) including explicit numerical evaluations; and (iii) an experimentally realistic synthesis and characterization protocol (materials, processing, and diagnostics). Using conservative but optimistic parameter choices supported by literature analogies (high-pressure hydrides and light-element clathrates), I find that the system can plausibly reach Tc in the high-temperature range (≈200–250 K) under idealized assumptions, and I quantify what improvements would be required to reach ~300 K. I identify the critical calculations and measurements needed to validate or falsify the design.

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