| Identifiers | |
|---|---|
3D model (JSmol) | |
| |
| |
| Properties | |
| H10La | |
| Molar mass | 148.985 g·mol−1 |
| Structure | |
| Cubic | |
| Fm3m | |
a = 5.1019(5) Å at 150 GPa | |
Lattice volume (V) | 132.80(4) Å3 |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
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 (22×106 psi), and its synthesis required pressures above approximately 160 gigapascals (23×106 psi). [6] [7]
Since its discovery in 2019, [5] the superconducting properties of LaH10 and other lanthanum-based superhydrides have been experimentally confirmed in multiple independent experiments. [8] [9] [10] [11] The compound exhibits a Meissner effect below the superconducting transition temperature. [12] 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. [13] Further reports indicate Tc is increased with nitrogen doping, [14] and decreased with the introduction of magnetic impurities. [15]
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. [16]
A similar compound, lanthanum boron octahydride, was computationally predicted to be a superconductor at 126 K (−147 °C; −233 °F) and pressure 50 gigapascals (7.3×106 psi). [17]