Lanthanum decahydride is a polyhydride or superhydride compound of lanthanum and hydrogen (LaH10) that has shown evidence of being a high-temperature superconductor. It was the first metal superhydride to be theoretically predicted,[2][3] synthesized,[4] and experimentally confirmed[5] to superconduct at near room-temperatures. It has a superconducting transition temperature TC around 250 K (−23 °C; −10 °F) at a pressure of 150 gigapascals (22×10 6 psi), and its synthesis required pressures above approximately 160 gigapascals (23×10 6 psi).[6][7]
Identifiers | |
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3D model (JSmol)
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Properties | |
H10La | |
Molar mass | 148.985 g·mol−1 |
Structure | |
Cubic | |
Fm3m | |
a = 5.1019(5) Å at 150 GPa
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Lattice volume (V)
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132.80(4) Å3 |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references
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Since its discovery,[8] the superconducting properties of LaH10 and other lanthanum-based superhydrides have been experimentally confirmed in multiple independent experiments.[9][10][11][12] The compound exhibits a Meissner effect below the superconducting transition temperature.[13] A cubic form can be synthesized at 1,000 K (730 °C; 1,340 °F),[6] and a hexagonal crystal structure can be formed at room temperature.[14] Further reports indicate Tc is increased with nitrogen doping,[15] and decreased with the introduction of magnetic impurities.[16]
The cubic form has each lanthanum atom surrounded by 32 hydrogen atoms, which form the vertices of an 18-faced shape called a chamfered cube.[17]
A similar compound, lanthanum boron octahydride, was computationally predicted to be a superconductor at 126 K (−147 °C; −233 °F) and pressure 50 gigapascals (7.3×10 6 psi).[18]