Physics and Chemistry of Minerals

, Volume 40, Issue 2, pp 183–193 | Cite as

New type of possible high-pressure polymorphism in NiAs minerals in planetary cores

  • Przemyslaw Dera
  • Jawad Nisar
  • Rajeev Ahuja
  • Sergey Tkachev
  • Vitali B. Prakapenka
Original Paper


The nickel arsenide (B81) and related crystal structures are among the most important crystallographic arrangements assumed by Fe and Ni compounds with light elements such as Si, O, S, and P, expected to be present in planetary cores. Despite the simple structure, some of these materials like troilite (FeS) exhibit complex phase diagrams and rich polymorphism, involving significant changes in interatomic bonding and physical properties. NiP (oP16) represents one of the two principal structure distortions found in the nickel arsenide family and is characterized by P–P bonding interactions that lead to the formation of P2 dimers. In the current study, the single-crystal synchrotron X-ray diffraction technique, aided by first principles density functional theory (DFT) calculations, has been applied to examine the compression behavior of NiP up to 30 GPa. Two new reversible displacive phase transitions leading to orthorhombic high-pressure phases with Pearson symbols oP40 and oC24 were found to occur at approximately 8.5 and 25.0 GPa, respectively. The oP40 phase has the primitive Pnma space group with unit cell a = 4.7729(5) Å, b = 16.6619(12) Å, and c = 5.8071(8) Å at 16.3(1) GPa and is a superstructure of the ambient oP16 phase with multiplicity of 2.5. The oC24 phase has the acentric Cmc21 space group with unit cell a = 9.695(6) Å, b = 5.7101(9) Å, and c = 4.7438(6) Å at 28.5(1) GPa and is a superstructure of the oP16 phase with multiplicity of 1.5. DFT calculations fully support the observed sequence of phase transitions. The two new phases constitute logical next stages of P sublattice polymerization, in which the dilution of the P3 units, introduced in the first high-pressure phase, decreases, leading to compositions of Ni20(P3)4(P2)4 and Ni12(P3)4, and provide important clues to understanding of phase relations and transformation pathways in the NiAs family.


Planetary cores Nickel arsenide structure NiP High pressure Phase transitions Polymorphism Bonding 


  1. Alsen N (1925) Roentgenographische Untersuchungen der Kristallstrukturen von Magnetkies, Breithauptit, Pentlandit, Millerit und verwandten Verbindungen. Geologiska Foereningens i Stockholm Foerhandlingar 47:19–73CrossRefGoogle Scholar
  2. Al-Sharif AI, Abu-Jafar M et al (2001) Structural and electronic structure properties of FeSi: the driving force behind the stability of the B20 phase. J Phys Cond Matter 13:2807CrossRefGoogle Scholar
  3. Birch F (1978) Finite strain isotherm and velocities for single-crystal and polycrystalline NaCl at high pressures and 300 K. J Geophys Res 83:1257–1268CrossRefGoogle Scholar
  4. Blochl PE (1994) Projector augmented-wave method. Phys Rev B 50:17953CrossRefGoogle Scholar
  5. Campbell AJ, Heinz DL (1993) Equation of state and high pressure phase transition of NiS in the NiAs structure. J Phys Chem Solids 54:5–7CrossRefGoogle Scholar
  6. Chen B, Li J et al (2008) Non-ideal liquidus curve in the Fe-S system and Mercury’s snowing core. Geophys Res Lett 35:L07201CrossRefGoogle Scholar
  7. Dera P (2007) GSE_ADA data analysis program for monochromatic single crystal diffraction with area detector. GSECARS, ChicagoGoogle Scholar
  8. Dera P, Lazarz JD et al (2011) Pressure-induced development of bonding in NiAs type compounds and polymorphism of NiP. J Solid State Chem 184:1997–2003CrossRefGoogle Scholar
  9. Dewaele A, Loubeyre P et al (2006) Quasihydrostatic equation of state iron above 2 Mbar. Phys Rev Lett 97:215504CrossRefGoogle Scholar
  10. Dobson DP, Vocadlo L et al (2002) A new high-pressure phase of FeSi. Am Miner 87:784–787Google Scholar
  11. Fei Y, Frost DJ et al (1999) In situ determination of the high-pressure phase of Fe3O4. Am Miner 84:203–206Google Scholar
  12. Garcia–Garcia FJ, Larsson AK (2005) X-ray powder diffraction and electron diffraction studies of the Ni1±yGe1–xPx system. J Solid State Chem 178:742–754CrossRefGoogle Scholar
  13. Grice JD, Ferguson RB (1974) Crystal structure refinement of millerite (B-NiS). Can Mineral 12:248–252Google Scholar
  14. Gu T, Wu X et al (2011) In situ high-pressure study of FeP: implications for planetary cores. Phys Earth Plan Interiors 184:154–159CrossRefGoogle Scholar
  15. Hauck SA, Aurnou JM et al (2006) Sulfur’s impact on core evolution and magnetic field generation on Ganymede. J Gophys Res 111:E09008CrossRefGoogle Scholar
  16. Ilnitskaya ON, Kuzma YB et al (1989a) New compound nickel silicide phosphide Ni2SiP and its crystal structure. Dopovidi Akademii Nauk Ukrains’koi RSR Series A: Fiziko-Matematichni Ta Tekhnichni Nauki 1989:79–81Google Scholar
  17. Ilnitskaya ON, Zavalii PY et al (1989b) The new compound Ni3.36Si1.76P6 and its crystal structure. Doklady Akademii Nauk Ukrainskoi SSR Series B: Geol. Khim. Biol Nauki 9:39–41Google Scholar
  18. Ilnitskaya ON, Bruskov VA et al (1991) New compound NiSi3P4 and its structure. Izvestiya Akademii Nauk SSSR Neorganicheskie Materialy 27:311–1313Google Scholar
  19. Ilnitskaya ON, Grin YN et al (1992) Crystal chemistry of series of nonuniform linear structures. IX: the series of nonuniform linear structures M2m+2nX2m+2n and its new representative Ni5Si2P3. Sov Phys Crystallogr 37:76–78Google Scholar
  20. Kresse G, Hafner J (1994) Ab initio molecular-dynamics simulation of the liquid-metal–amorphous-semiconductor transition in germanium. Phys Rev B 49:14251–14269CrossRefGoogle Scholar
  21. Kresse G, Joubert D (1999) From ultrasoft pseudopotentials to the projector augmented-wave method. Phys Rev B 59:1758–1775CrossRefGoogle Scholar
  22. Larsson E (1965) An X-ray investigation of the Ni-P system and the crystal structures of NiP and NiP2. Ark Kemi 23:335–365Google Scholar
  23. Larsson AK, Garcia–Garcia FJ et al (2007) The incommensurately modulated NiGe1-xPx, ~ 0.3 ≤ x ≤ ~ 0.7, solid solution: the ‘missing link’ between the NiP and MnP structure types. J Solid State Chem 180:1093–1102CrossRefGoogle Scholar
  24. Lee KJ, Nash P (1991) Phase diagrams of binary nickel alloys. ASM International, Materials Park, pp 235–246Google Scholar
  25. Lin JF, Campbell AJ et al (2003a) Static compression of iron-silicon alloys: implications for silicon in the Earth’s core. J Geophys Res 108:2045CrossRefGoogle Scholar
  26. Lin JF, Struzhkin VV et al (2003b) Sound velocities of iron-nickel and iron-silicon alloys in the earth’s core. Geophys Res Lett 30:2112CrossRefGoogle Scholar
  27. Mao HK, Xu J et al (1986) Calibration of the ruby pressure gauge to 800 kbar under quasi-hydrostatic conditions. J Geophys Res 91:4673–4676CrossRefGoogle Scholar
  28. Mao HK, Wu Y et al (1990) Static compression of iron to 300 GPa and Fe0.8Ni0.2 alloy to 260 GPa: implications for the composition of the core. J Geophys Res 95:737–742CrossRefGoogle Scholar
  29. Marshall WG, Nelmes RJ et al (2000) High-pressure neutron-diffraction study of FeS. Phys Rev B 61:11201–11204CrossRefGoogle Scholar
  30. Martin P, Price GD et al (2001) An ab initio study of the relative stabilities and equations of state of FeS polymorphs. Mineral Mag 65:181–191CrossRefGoogle Scholar
  31. McDonough WF (2003) Compositional model for the earth’s core. The mantle and core. R. W. Carlson, Oxford, pp 547–568Google Scholar
  32. McDonough WF, Sun SS (1995) The composition of the earth. Chem Geol 120:223–253CrossRefGoogle Scholar
  33. Monkhorst HJ, Pack JD (1976) Special points for Brillouin-zone integrations. Phys Rev B 13:5188–5192CrossRefGoogle Scholar
  34. Nazarov MA, Kurat G et al (2009) Phosphorus-bearing sulfides and their associations in CM chondrites. Petrology 17:101–123CrossRefGoogle Scholar
  35. Nelmes RJ, McMahon MI et al (1999) Structure of the high-pressure phase III of iron sulfide. Phys Rev B 59:9048–9052CrossRefGoogle Scholar
  36. Nisar J, Ahuja R (2010) Equation of state (EOS) and collapse of magnetism in iron-rich meteorites at high pressure by first-principles calculations. Phys Earth Planet Interiors 182:175–178CrossRefGoogle Scholar
  37. Ono S, Oganov AR et al (2008) High-pressure transformations of FeS: novel phases at conditions of planetary cores. Earth Planet Sci Lett 272:481–487CrossRefGoogle Scholar
  38. Oryshchyn SV, Babizhetsky VS et al (1999) Preparation and crystal structure of Ni7Si2P5. Zeitschr Krist 214:337–340CrossRefGoogle Scholar
  39. Oyama ST (2003) Novel catalysts for advanced hydroprocessing: transition metal phosphides. J Catal 216:343–352CrossRefGoogle Scholar
  40. Ozawa H, Hirose K et al (2011) Spin crossover, structural change, and metallization in NiAs-type FeO at high pressure. Phys Rev B 84:134417CrossRefGoogle Scholar
  41. Perdew JP, Wang Y (1992) Accurate and simple analytic representation of the electron-gas correlation energy. Phys Rev B 45:13244–13249CrossRefGoogle Scholar
  42. Perdew JP, Chevary JA et al (1992) Atoms, molecules, solids, and surfaces: applications of the generalized gradient approximation for exchange and correlation. Phys Rev B 46:6671–6687CrossRefGoogle Scholar
  43. Perdew JP, Burke K et al (1996a) Generalized gradient approximation made simple. Phys Rev Lett 77:3865–3868CrossRefGoogle Scholar
  44. Perdew JP, Burke K et al (1996b) Errata. Generalized gradient approximation made simple. Phys Rev Lett 78:1396CrossRefGoogle Scholar
  45. Putz H, Schon JC et al (2009) Endeavour. Bonn, crystal impact GbR.
  46. Putz H, Schon JC et al (1999) Method for’Ab Initio’ structure solution from powder diffraction data. J Appl Cryst 32:864–870CrossRefGoogle Scholar
  47. Rajamani V, Prewitt CT (1974) The crystal structure of millerite. Can Mineralog 12:253–257Google Scholar
  48. Ren J, Wang JG et al (2007) Density functional theory study on crystal nickel phosphides. J Fuel Chem Technol 35:458–464CrossRefGoogle Scholar
  49. Rivers ML, Prakapenka VB et al (2008) The COMPRES/GSECARS gas loading system for diamond anvil cells at the Advanced Photon Source. High Press Res 28:273–292CrossRefGoogle Scholar
  50. Sheldrick GM (2008) A short history of SHELX. Acta Cryst A64:112–122Google Scholar
  51. Sowa H, Ahsbahs H et al (2004) X-ray diffraction studies of millerite NiS under non-ambient conditions. Phys Chem Miner 31:321–327CrossRefGoogle Scholar
  52. Thompson JG, Rae AD et al (1988) The crystal structure of nickel arsenide. J Phys C: Solid State Phys 21:4007–4015CrossRefGoogle Scholar
  53. Tremel W, Hoffmann R et al (1986) Transitions between NiAs and MnP type phases: an electronically driven distortion of triangular (36) nets. J Am Chem Soc 108:5174–5187CrossRefGoogle Scholar
  54. Vočadlo L, Wood IG et al (1999) Crystal structure, compressibility and possible phase transitions in epsilon-FeSi studied by first-principles pseudopotential calculations. Acta Cryst. B 55:484–493CrossRefGoogle Scholar
  55. Williams Q, Jeanloz R (1990) Melting relations in the iron-sulfur system at ultrahigh pressures: implications for the thermal state of the earth. J Geophys Res 95:19299–19310CrossRefGoogle Scholar
  56. Wu X, Mookherjee M et al (2011) Elasticity and anisotropy of iron-nickel phosphides at high pressures. Geophys Res Lett 38:L20301CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2012

Authors and Affiliations

  • Przemyslaw Dera
    • 1
  • Jawad Nisar
    • 2
  • Rajeev Ahuja
    • 2
    • 3
  • Sergey Tkachev
    • 1
  • Vitali B. Prakapenka
    • 1
  1. 1.Center for Advanced Radiation SourcesThe University of Chicago, Argonne National LaboratoryArgonneUSA
  2. 2.Condensed Matter Theory Group, Department of Physics and AstronomyUppsala UniversityUppsalaSweden
  3. 3.Applied Materials Physics, Department of Materials and EngineeringRoyal Institute of Technology (KTH)StockholmSweden

Personalised recommendations