TY - JOUR

T1 - Phase Stability in Nickel Phosphides at High Pressures

AU - Inerbaev, Talgat M.

AU - Sagatov, Nursultan

AU - Sagatova, Dinara

AU - Gavryushkin, Pavel N.

AU - Akilbekov, Abdirash T.

AU - Litasov, Konstantin D.

N1 - Funding Information: The authors are thankful to the Center for Computational Materials Science, Institute for Materials Research, Tohoku University and Novosibirsk University Supercomputing Center for their continuous support of the supercomputing system to be used for our simulation works. The reported calculations of crystal structure prediction were funded by RFBR project number 19-35-90043, and the calculations of PT diagrams were funded by the state assignment project of IGM SB RAS. Publisher Copyright: © 2020 American Chemical Society. Copyright: Copyright 2020 Elsevier B.V., All rights reserved.

PY - 2020/11/19

Y1 - 2020/11/19

N2 - Phosphorus is one of the potential light elements of the core of the Earth and other planets. The high-pressure behavior of phosphorus compounds with nickel and iron attracts considerable attention due to their abundance in iron meteorites. In the present work, with modern methods of crystal structure prediction, we investigate the structures and stability of compounds in the Ni-P system at pressures of 100-400 GPa. As a result, a homologous series of discrete compounds (Ni, P), consisting of Ni14P, Ni12P, Ni10 P, Ni8P, Ni7P, Ni5P, and Ni3P was found. Phosphorus shows sufficient solubility in the face-centered cubic (fcc) structure of Ni, and up to 25 mol % of this element can be dissolved at low temperatures. Based on the comparison of compounds in the Ni-P and Fe-P systems, we suggest that at high pressures Ni facilitates phosphorus dissolution in the closed-packed structure of d-metals, and dissolution of P in the (Ni, P) alloy will be higher than that in pure Fe. For the Ni3P compound, a new high-pressure phase with the Cmca symmetry is predicted. This structure can be described as deformed fcc packing and also belongs to the ordered representatives of the series of (Ni, P) solid solutions. The transition from the low-pressure phase of Ni3P-I4¯ to the Cmca phase occurs at a pressure of 62 GPa, regardless of the external temperature. Ni2P is stabilized at a pressure above 200 GPa in the form of an allabogdanite structure. The transition from transjordanite to allabogdanite occurs at 78-88 GPa and 0-2000 K.

AB - Phosphorus is one of the potential light elements of the core of the Earth and other planets. The high-pressure behavior of phosphorus compounds with nickel and iron attracts considerable attention due to their abundance in iron meteorites. In the present work, with modern methods of crystal structure prediction, we investigate the structures and stability of compounds in the Ni-P system at pressures of 100-400 GPa. As a result, a homologous series of discrete compounds (Ni, P), consisting of Ni14P, Ni12P, Ni10 P, Ni8P, Ni7P, Ni5P, and Ni3P was found. Phosphorus shows sufficient solubility in the face-centered cubic (fcc) structure of Ni, and up to 25 mol % of this element can be dissolved at low temperatures. Based on the comparison of compounds in the Ni-P and Fe-P systems, we suggest that at high pressures Ni facilitates phosphorus dissolution in the closed-packed structure of d-metals, and dissolution of P in the (Ni, P) alloy will be higher than that in pure Fe. For the Ni3P compound, a new high-pressure phase with the Cmca symmetry is predicted. This structure can be described as deformed fcc packing and also belongs to the ordered representatives of the series of (Ni, P) solid solutions. The transition from the low-pressure phase of Ni3P-I4¯ to the Cmca phase occurs at a pressure of 62 GPa, regardless of the external temperature. Ni2P is stabilized at a pressure above 200 GPa in the form of an allabogdanite structure. The transition from transjordanite to allabogdanite occurs at 78-88 GPa and 0-2000 K.

KW - crystal structure prediction

KW - density functional theory

KW - phase stability

KW - phase transitions

KW - polymorphism

UR - http://www.scopus.com/inward/record.url?scp=85095998465&partnerID=8YFLogxK

U2 - 10.1021/acsearthspacechem.0c00181

DO - 10.1021/acsearthspacechem.0c00181

M3 - Article

AN - SCOPUS:85095998465

VL - 4

SP - 1978

EP - 1984

JO - ACS Earth and Space Chemistry

JF - ACS Earth and Space Chemistry

SN - 2472-3452

IS - 11

ER -