Metal Hexaborides with Sc, Ti or Mn


Comparison of well-determined single crystal data for stoichiometric, or near-stoichiometric, metal hexaborides confirms previously identified lattice parameter trends using powder diffraction. Trends for both divalent and trivalent forms suggest that potential new forms for synthesis include Sc and Mn hexaborides. Density Functional Theory (DFT) calculations for KB6, CaB6, YB6, LaB6, boron octahedral clusters and Sc and Mn forms show that the shapes of bonding orbitals are defined by the boron framework. Inclusion of metal into the boron framework induces a reduction in energy ranging from 1 eV to 6 eV increasing with ionic charge. For metals with d1 character, such a shift in energy brings a doubly degenerate band section along with the G-M reciprocal space direction within the conduction bands tangential to the Fermi surface. ScB6 band structure and density of states calculations show directions and gap characteristics similar to those of YB6 and LaB6. These calculations for ScB6 suggest that it may be possible to realize superconductivity in this compound if synthesized.

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I. Mackinnon, J. Alarco and P. Talbot, "Metal Hexaborides with Sc, Ti or Mn," Modeling and Numerical Simulation of Material Science, Vol. 3 No. 4, 2013, pp. 158-169. doi: 10.4236/mnsms.2013.34023.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] T. H. Geballe, K. Andres, E. Corenzwit, G. W. Hull and J. P. Maita, “Superconductivity and Antiferromagnetism in Boron-Rich Lattices,” Science, Vol. 159, No. 3814, 1968, pp. 530-531.
[2] S. Souma, H. Komoda, Y. Iida, T. Sato, T. Takahashi and S. Kunii, “Direct Observation of Superconducting Gap in YB6 by Ultrahigh-Resolution Photoelectron Spectroscopy,” Journal of Electron Spectroscopy and Related Phenomena, Vol. 144-147, 2005, pp. 503-506.
[3] R. J. Sobczak and M. J. Sienko, “Superconductivity in the Hexaborides,” Journal of the Less Common Metals, Vol. 67, No. 1, 1979, pp. 167-171.
[4] J.-P. Mercurio, J. Etourneau, R. Naslain, P. Hagenmuller and J. B. Goodenough, “Proprietes Electriques et Magnetiques des Solutions Solides LaxEu1-xB6,” Journal of Solid State Chemistry, Vol. 9, No. 1, 1974, pp. 37-47.
[5] B. K. Cho, J.-S. Rhyee, B. H. Oh, M. H. Jung, H. C. Kim, Y. K. Yoon, J. H. Kim and T. Ekino, “Formation of Midgap States and Ferromagnetism in Semiconducting CaB6,” Physical Review B, Vol. 69, No. 11, 2004, Article ID: 113202.
[6] C.-H. Chen, T. Aizawa, N. Iyi, A. Sato and S. Otani, “Structural Refinement and Thermal Expansion of Hexaborides,” Journal of Alloys and Compounds, Vol. 366, No. 1-2, 2004, pp. L6-L8.
[7] J. M. Tarascon, Y. Isikawa, B. Chevalier, J. Etourneau and P. Hagenmuller, “Valence Transition of Samarium in Hexaboride Solid Solutions Sm1-xMxB6 (M=Yb2+, Sr2+, La3+, Y3+, Th4+),” Journal of Physique, Vol. 41, No. 10, 1980, pp. 1125-1140.
[8] M. K. Blomberg, M. J. Merisalo, M. M. Korsukova and V. N. Gurin, “Single-Crystal X-Ray Diffraction Study of NdB6, EuB6 and YbB6,” Journal of Alloys and Compounds, Vol. 217, No. 1, 1995, pp. 123-127.
[9] Z. Yahia, S. Turrell, G. Turrell and J. P. Mercurio, “Infra-red and Raman Spectra of Hexaborides: Force-Field Calculations and Isotopic Effects,” Journal of Molecular Structure, Vol. 224, 1990, pp. 303-312.
[10] S. Otani, H. Nakagawa, Y. Nishi and N. Kieda, “Floating Zone Growth and High Temperature Hardness of Rare- Earth Hexaboride Crystals: LaB6, CeB6, PrB6, NdB6, and SmB6,” Journal of Solid State Chemistry, Vol. 154, No. 1, 2000, pp. 238-241.
[11] J. Etourneau, A. Ammar, A. Villesuzanne, G. Villeneuve, B. Chevalier and M.-H. Whangbo, “Unusual Hysteresis in the Magnetic Susceptibility of Cubic Hexaboride KB6,” Inorganic Chemistry, Vol. 42, No. 14, 2003, pp. 4242- 4244.
[12] A. Ammar, M. Menetrier, A. Villesuzanne, S. Matar, B. Chevalier and J. Etourneau, “Investigation of the Electronic and Structural Properties of Potassium Hexaboride, KB6, by Transport, Magnetic Susceptibility, EPR and NMR Measurements, Temperature-Dependent Crystal Structure Determination, and Electronic Band Structure Calculations,” Inorganic Chemistry, Vol. 43, No. 16, 2004, pp. 4974-4987.
[13] T. Konrad, W. Jeitschko, M. E. Danebrock and C. B. H. Evers, “Preparation, Properties and Crystal Structures of the Thorium Chromium Borides ThCrB4 and ThCr2B6; Structure Refinements of CeCr2B6, ThB4 and ThB6,” Journal of Alloys and Compounds, Vol. 234, No. 1, 1996, pp. 56-61.
[14] S. F. Matar and J. Etourneau, “The Electronic Structures of Uranium Borides from Local Spin Density Functional Calculations,” International Journal of Inorganic Materials, Vol. 2, No. 1, 2000, pp. 43-51.
[15] L.-H. Bao, J.-X. Zhang, S.-L. Zhou and Tegus, “Synthesis, Thermionic Emission and Magnetic Properties of (NdxGd1-x)B6,” Chinese Physics B, Vol. 20, No. 5, 2011, Article ID: 058101.
[16] J.-M. Mignot, G. Andre, M. Sera and F. Iga, “Magnetic Phase Diagram of CexNd1-xB6 Solid Solutions,” Journal of Magnetism and Magnetic Materials, Vol. 310, No. 2, 2007, pp. 738-740.
[17] M. K. Blomberg, M. J. Mersialo, M. M. Korsukova and V. N. Gurin, “Single-Crystal X-Ray Diffraction Study on Ce1-xLaxB6 Solid Solutions,” Journal of the Less Common Metals, Vol. 168, No. 2, 1991, pp. 313-319.
[18] L. Vegard, “Die Konstitution der Mischkristalle und die Raumfüllung der Atome,” Zeitschrift für Physik, Vol. 5, No. 1, 1921, pp. 17-26.
[19] G. A. Wigger, C. Beeli, E. Felder, H. R. Ott, A. D. Bianchi and Z. Fisk, “Percolation and the Colossal Magnetoresistance of Eu-Based Hexaboride,” Physical Review Letters, Vol. 93, No. 14, 2004, Article ID: 147203.
[20] V. I. Matkovich, Ed., “Boron and Refractory Borides,” Springer-Verlag, Berlin, 1977, 656 p.
[21] P. G. Perkins, “The Electronic Structures of the Hexaborides and the Diborides,” In: V. I. Matkovich, Ed., Boron and Refractory Borides, Springer-Verlag, Berlin, 1977, pp. 31-51.
[22] S. J. Clark, M. D. Segall, C. J. Pickard, P. J. Hasnip, M. J. Probert, K. Refson and M. C. Payne, “First Principles Methods Using CASTEP,” Zeitschrift fur Kristall, Vol. 220, No. 5-6, 2005, pp. 567-570.
[23] D. S. Sholl and J. A. Steckel, “Density Functional Theory —A Practical Introduction,” Wiley, Hoboken, 2009.
[24] V. Milman, B. Winkler, J. A. White, C. J. Pickard, M. C. Payne, E. V. Akhmatskaya and R. H. Nobes, “Electronic Structure, Properties, and Phase Stability of Inorganic Crystals: A Pseudopotential Plane-Wave Study,” International Journal of Quantum Chemistry, Vol. 77, No. 5, 2000, pp. 895-910.<895::AID-QUA10>3.0.CO;2-C
[25] F. M. Hossain, D. P. Riley and G. E. Murch, “Ab Initio Calculations of the Electronic Structure and Bonding Characteristics of LaB6,” Physical Review B, Vol. 72, No. 23, 2005, Article ID: 235101.
[26] G. Ning and R. L. Flemming, “Rietveld Refinement of LaB6: Data from μXRD,” Journal of Applied Crystallography, Vol. 38, 2005, pp. 757-759.
[27] A. Malyshev, D. Chernyshov, V. Trounov, V. Gurin and M. Korsukova, “Crystal Structure of Nd11B6 in the Temperature Range 23-300K: A High-Resolution Powder Neutron Diffraction Study,” Proceedings of the 11th International Symposium on Boron, Borides and Related Compounds, JJAP Series 10, 1994, pp. 19-20.
[28] K. Tanaka and Y. Onuki, “Observation of 4f Electron Transfer from Ce to B6 in the Kondo Crystal CeB6 and Its Mechanism by Multi-Temperature X-Ray Diffraction,” Acta Crystallographica, Vol. B58, 2002, pp. 423-436.
[29] S. Funahashi, K. Tanaka and F. Iga, “X-Ray Atomic Orbital Analysis of 4f and 5d Electron Configuration of SmB6 at 100, 165, 230 and 298K,” Acta Crystallographica, Vol. B66, 2010, pp. 292-306.
[30] N. Ogita, S. Nagai, N. Okamoto, F. Iga, S. Kunii, J. Akimitsu and M. Udagawa, “Raman Scattering Study of Hexaboride Crystals,” Physica B, Vol. 328, No. 1-2, 2003, pp. 131-134.
[31] D. Yu Chernyshov, M. B. Smirnov, A. V. Menshikova, A. P. Mirogodosky and V. A. Trounov, “Mean Square Displacements of Atoms in Hexaborides,” Physica B, Vol. 234-236, 1997, pp. 146-148.
[32] R. D. Shannon, “Revised Effective Ionic Radii and Systematic Studies of Interatomic Distances in Halides and Chalcogenides,” Acta Crystallographica, Vol. A32, 1976, pp. 751-767.
[33] G. E. Grechnev, A. E. Baranovskiy, V. D. Fil, T. V. Ignatova, N. Yu. Shitsevalova, V. B. Filippov and O. Eriksson, “Electronic Structure and Bulk Properties of MB6 and MB12 Borides,” Low Temperature Physics, Vol. 34, No. 11, 2008, pp. 921-929.
[34] K. Schmitt, C. Stuckl, H. Ripplinger and B. Albert, “Crystal and Electronic Structure of BaB6 in Comparison with CaB6 and Molecular [B6H6]-2,” Solid State Sciences, Vol. 3, 2001, pp. 321-327.
[35] G. Mair, H.-G. von Schnering, M. Worle and R. Nesper, “Dilithium Hexaboride, Li2B6,” Zeitschrift für Anorganische und Allgemeine Chemie, Vol. 625, No. 7, 1999, pp. 1207-1211.<1207::AID-ZAAC1207>3.0.CO;2-9
[36] G. Barantseva and B. P. Yu, “Possibility of Existence of Scandium Hexaboride,” Test Methods and Properties of Powder Metallurgical Materials, Plenum Publishing Corp., 1982, pp. 56-60.
[37] Y. Xu, L. Zhang, T. Cui, Y. Li, Y. Xie, W. Yu, Y. Ma and G. Zou, “First-Principles Study of the Lattice Dynamics, Thermodynamic Properties and Electron-Phonon Coupling of YB6,” Physical Review B, Vol. 76, No. 21, 2007, Article ID: 214103.
[38] K. Shirai and N. Uemura, “Why Does a Metal Get an Insulator? Consequences of Unfilled Bands on Boron Crystals,” Solid State Sciences, Vol. 14, No. 11-12, 2012, pp. 1609-1616.
[39] F. Thevenot, “Boron Carbide—A Comprehensive Review,” Journal of the European Ceramic Society, Vol. 6, No. 4, 1990, pp. 205-225.
[40] I. R. Shein, K. I. Shein, G. P. Shveikin and A. L. Ivanoskii, “Electronic Structure of Cubic Thorium Monocarbide and Hexaboride,” Doklady Physical Chemistry, Vol. 407, No. 2, 2006, pp. 106-109.
[41] J. Etourneau, R. Naslain and S. La Placa, “L’Hexaborure de Thorium Non-Stoechiometrique Th1-xB6,” Journal of the Less Common Metals, Vol. 24, No. 2, 1971, pp. 183- 194.
[42] V. A. Trunov, A. L. Malyshev, D. Yu Chernyshov, A. I. Kurbakov, M. M. Korsukova, V. N. Gurin, L. A. Aslanov and V. V. Chernyshev, “Isotopic Engineering of ‘Zero- Matrix’ Samarium Hexaboride: Results of High-Resolution Powder Neutron Diffraction and X-Ray Single-Crystal Diffratometry Studies,” Journal of Applied Crystallography, Vol. 24, 1991, pp. 888-892.
[43] Y. Katsura, A. Yamamoto, H. Ogino, S. Horii, J. Shimoyama, K. Kishio and H. Takagi, “On the Possibility of MgB2-Like Superconductivity in Potassium Hexaboride,” Physica C, Vol. 470, 2010, pp. S633-S634.
[44] D. P. Young, D. Hall, M. E. Torelli, Z. Fisk, J. L. Sarrao, J. D. Thompson, H.-R. Ott, S. B. Oseroff, R. G. Goodrich and R. Zysler, “High-Temperature Weak Ferromagnetism in a Low-Density Free-Electron Gas,” Nature, Vol. 397, 1999, pp. 412-414.
[45] Z. Yahia, S. Turrell, J.-P. Mercurio and G. Turrell, “Spectroscopic Investigation of Lattice Vacancies in Hexaborides,” Journal of Raman Spectroscopy, Vol. 24, No. 4, 1993, pp. 207-212.
[46] B. Jager, S. Paluch, W. Wolf, P. Herzig, O. J. Zogal, N. Shitsevalova and Y. Paderno, “Characterization of the Electronic Properties of YB4 and YB6 Using 11B NMR and First-Principles Calculations,” Journal of Alloys and Compounds, Vol. 383, No. 1-2, 2004, pp. 232-238.
[47] A. M. Gabovich, A. I. Voitenko and M. Ausloos, “Charge and Spin-Density Waves in Existing Superconductors: Competition between Cooper Pairing and Peierls or Excitonic Instabilities,” Physics Reports, Vol. 367, 2002, pp. 583-709.
[48] B. Albert and K. Schmitt, “New Boron-Rich Materials: Cubic Carbaborides of Sodium and Potassium,” Chemistry of Materials, Vol. 11, No. 11, 1999, pp. 3406-3409.

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