# Ab initio study on the effects of transition metal doping of Mg2NiH4

Source: [Ab initio study on the effects of transition metal doping of Mg2NiH4](<https://www.sota2.com/research/paper/68fa210e7a2b558e29334ee9>)

Collection index: [llms.txt](<https://www.sota2.com/research/llms.txt>)

Data updated: 2025-10-23T23:57:03.667Z

Authors: M.J. van Setten, G.A. de Wijs, G. Brocks

Published: 2007-03-21T13:36:25.000Z

## Abstract

Mg2NiH4 is a promising hydrogen storage material with fast (de)hydrogenation kinetics. Its hydrogen desorption enthalpy, however, is too large for practical applications. In this paper we study the effects of transition metal doping by first-principles density functional theory calculations. We show that the hydrogen desorption enthalpy can be reduced by ~0.1 eV/H2 if one in eight Ni atoms is replaced by Cu or Fe. Replacing Ni by Co atoms, however, increases the hydrogen desorption enthalpy. We study the thermodynamic stability of the dopants in the hydrogenated and dehydrogenated phases. Doping with Co or Cu leads to marginally stable compounds, whereas doping with Fe leads to an unstable compound. The optical response of Mg2NiH4 is also substantially affected by doping. The optical gap in Mg2NiH4 is ~1.7 eV. Doping with Co, Fe or Cu leads to impurity bands that reduce the optical gap by up to 0.5 eV.

## Recorded benchmark results

A research result applies to its stated dataset, split, metric and evaluation configuration. Compare like-for-like settings, preserve the metric's unit and direction, and distinguish paper-reported results from independent reproduction. The best result recorded here is not a claim of exhaustive, current global coverage.

## Original sources and implementation

[Original paper](<https://arxiv.org/abs/cond-mat/0703550>)

[PDF](<https://arxiv.org/pdf/cond-mat/0703550.pdf>)