The first magnesium–chromium hydride synthesized by the gigapascal high-pressure technique

A new ternary magnesium–titanium hydride Mg7TiH with hydrogen desorption properties better than both binary magnesium and titanium hydrides

“…The MgH 2 -TiH 1.9 pellet was enclosed together with two pellets of the hydrogen-source, separated by BN discs, in a NaCl capsule, which was surrounded with a carbon heater, placed at the centre of a pyrophyllite octahedron. Details of this setup can be found in the previous reports [4,12,13]. The cell was compressed almost isotropically up to 8 GPa by using a high-pressure generating machine with six to eight multi-anvils.…”

“…No binary Mg 7 Ti, however, existed after releasing hydrogen. Therefore this ternary hydride can only exist by the support of hydrogen atoms as is the case for most complex type metal hydrides, such as NaAlH 4 . Under gigapascal high pressure, hydrogen can stabilize metastable metal atom structures, and it is expected to create other novel metal hydrides.…”

“…However the hydrogen absorption and desorption kinetics are slow, necessitating higher temperature compared to other metal hydride systems. By reacting magnesium or magnesium hydride with the first row transition metals new hydrides based on transition metal-hydrido complexes have been synthesized and characterized, Mg 3 MnH 7 [1], Mg 3 MnH ∼6 [2,3] and Mg 3 CrH x [4,5]. More drastic improvement without reducing the advantageous storage properties is, however, required for practical applications.…”

Electrochemical Hydrogen Storage Characteristics of Thin Film MgX (X=Sc, Ti, V, Cr) Compounds

“…8 During the last few years, several researchers have investigated both the preparation and the hydrogen sorption characteristics of the MgTi, MgV, and MgCr systems. Kyoi 11,12 Although the complexity of the anvil-cell technique is very high and the conditions applied very extreme, it shows that crystalline MgX hydrides ͑X = Ti, V, Cr͒ can exist in bulk form. Until now, only a few researchers have tried to synthesize and characterize the same compounds via a thin film approach.…”

Structural characterization of Mg3CrH∼6—a new high-pressure phase synthesized in a multi-anvil cell at 8 GPa

“…We successfully identified the metal atom structure to consist of manganese hydrido complexes counterbalanced by magnesium ions, Mg 3 MnH ∼6 [4]. We are continuing searching for new Mg-based ternary metal hydrides by using the gigapascal high-pressure thermal technique and recently we reported our findings in the Mg-Cr-H system [5]. Chromium hydrido complexes so far not been reported in the literature, but at the MH2002 conference in Annecy the first chromium hydridometalate, ACrH 3 (A: K, Rb) was reported by Auffermann and Bronger [6].…”