Magnesium nickel hydride - presumable smart material for energy related applications

Abstract

Magnesium nickel hydride Mg2NiH4 was discovery by Reilly and Wiswall in 1968 [1]. Since then it became a target of many fundamental and application (mainly hydrogen storage) driven studies. It was revealed that in powder form Mg2NiH4 has three crystal phases: LT-1 and LT-2 are both monoclinic low temperature (below 510 K) phases respectively without and with microtwinings [2-3], and HT is FCC non-conducting high temperature (above 510 K) phase. For Mg2NiH4 powders, phase transition between low temperature and high temperature phases is reversible [3]. Each of these phases has unique optical and electrical properties, therefore properly using these phase transitions could lead to the creation of smart material presumably suitable for smart windows devices, new generation of wide band gap solar cells or even metal hydride batteries. This presentation reviews main requirements and available fundamental prerequisites for Mg2NiH4 to be used as smart material for energy applications.