Formation of transition metal hydrides at high pressures

Degtyareva, Olga; Proctor, John E.; Guillaume, Christophe L.; Gregoryanz, Eugene; Hanfland, Michael

doi:10.1016/j.ssc.2009.07.022

Cited by 105 publications

(90 citation statements)

References 35 publications

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“…An early form of the AIRSS structure searching method was used to find more stable structures in an overnight run on a standard single processor machine. 31 Structures that we had found of SiH 4 with I4 1 /a and I42d symmetries were subsequently verified by X-ray diffraction experiments, 53,54 although the I4 1 /a phase is insulating, see Fig. 4.…”

Section: Superconducting Hydridessupporting

confidence: 53%

Perspective: Role of structure prediction in materials discovery and design

Needs¹,

Pickard

2016

APL Materials

124

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Materials informatics owes much to bioinformatics and the Materials Genome Initiative has been inspired by the Human Genome Project. But there is more to bioinformatics than genomes, and the same is true for materials informatics. Here we describe the rapidly expanding role of searching for structures of materials using first-principles electronic-structure methods. Structure searching has played an important part in unraveling structures of dense hydrogen and in identifying the record-high-temperature superconducting component in hydrogen sulfide at high pressures. We suggest that first-principles structure searching has already demonstrated its ability to determine structures of a wide range of materials and that it will play a central and increasing part in materials discovery and design.

show abstract

Section: Superconducting Hydridessupporting

confidence: 53%

Perspective: Role of structure prediction in materials discovery and design

Needs¹,

Pickard

2016

APL Materials

124

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“…This polymorph of silane has also a small band-gap as it is opaque in visible light. At 50 GPa silane is observed to become amorphous and partially decompose [6]. This new finding contradicts earlier claims that a metallic phase of silane is formed above 50 GPa [7] -the reported "metallic" phase can most probably be attributed to PtH x (coincidentally obtained from Pt foil used to measure resistance of the sample, and H 2 evolving from silane [6]).…”

Section: Introductioncontrasting

confidence: 57%

“…The use of phonon--guided optimization enables us to further propose that ‡ The X-ray diffraction pattern of F dd2 does not reproduce two new peaks observed for compressed SiH 4 above 25 GPa (Ref. [6]). We notice that these two peaks cannot be unambiguously assigned to a new phase of SiH 4 as Ref.…”

Section: Phonon-guided Optimizationmentioning

confidence: 99%

Phonon Dispersion Analysis as an Indispensable Tool for Predictions of Solid State Polymorphism and Dynamic Metastability: Case of Compressed Silane

Kurzydłowski

Grochala

2011

Acta Phys. Pol. A

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This work is dedicated to Prof. Russell J. Hemley in recognition of his seminal contributions to high pressure sciencesDiamond anvil cell experiments suggest that upon compression above 26.5 GPa silane (SiH 4 ) forms a polymeric phase VI, whose crystal structure has not yet been solved. Here we present DFT calculations showing how phonon-guided optimization leads to a polymeric F dd2 structure which is the lowest-enthalpy polymorph of SiH 4 above 26.8 GPa, and which most probably can be identified as the experimentally observed polymeric phase. The new algorithm of predicting the lowest-energy structures enables simultaneous inspection of the potential energy surface of a given system, calculation of its vibrational properties, and assessment of chances for obtaining a metastable ambient-pressure structure via decompression. Our calculations indicate that at room temperature the differences in the vibrational and entropy terms contributing to the Gibbs free energy of different polymorphs of silane are negligible in comparison with corresponding differences in the zero-point energy corrections, in contrast to earlier suggestions. We also show that the F dd2 polymorph should be metastable upon decompression up to 5 GPa, which suggests the possibility of obtaining a polymeric ambient-pressure form of SiH 4 . Polymeric silane should exhibit facile thermal decomposition with evolution of molecular hydrogen and thus constitute an efficient (12.5 wt%) material for hydrogen storage.

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“…15 This discovery gives a well explanation for the differences between experimental and theoretical studies of high pressure phase of silane. 6,8,10,11,14 The calculated lattice constants, the simulated XRD pattern, and the superconducting transition temperature for platinum hydride are in good agreement with the previously published experimental results.…”

Section: Discussionmentioning

confidence: 81%

“…Degtyareva et al 15 showed that the experimental XRD pattern can be explained by the formation of a platinum hydride due to the reaction of hydrogen (originating from the decomposed silane) with platinum electrodes (used for measuring conductivity). However, the structure and exact composition of this platinum hydride are not determined, and it is still unknown whether platinum hydride(s) can explain peculiar superconductivity observed in Ref.…”

mentioning

confidence: 99%

Superconducting high-pressure phase of platinum hydride from first principles

et al. 2011

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Recently a superconducting transition was found in silane in high-pressure experiments. However, the experimental x-ray diffraction (XRD) patterns do not match any one of proposed silane structures, and it has been suggested to be originated from a platinum hydride. Neither the structure nor superconductivity of any platinum hydride is known. Here the underlying physics behind the anomalous superconducting transition in experiment is revealed by first-principles calculations. We predict a stable hexagonal P63/mmc phase of platinum hydride at high pressure. Its lattice constants and simulated XRD pattern are in excellent agreement with the experimental results. The superconducting transition temperatures in this phase are found to coincide with the measured values, too. This discovery provides new insights into the unusual superconducting behavior reported for silane.

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Formation of transition metal hydrides at high pressures

Cited by 105 publications

References 35 publications

Perspective: Role of structure prediction in materials discovery and design

Perspective: Role of structure prediction in materials discovery and design

Phonon Dispersion Analysis as an Indispensable Tool for Predictions of Solid State Polymorphism and Dynamic Metastability: Case of Compressed Silane

Superconducting high-pressure phase of platinum hydride from first principles

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