Magnetism tuning in non-centrosymmetric chiral semiconductor CeRhC2

• Applicants: Professor Juri Grin; Volodymyr Levytskyi, Ph.D.
• Subject Area: Solid State and Surface Chemistry, Material Synthesis
• Term: from 2021 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 467257848

• Final Report Year: 2025

Final Report Abstract

RRhC2 (R = La, Ce) semiconductors are the only rare-earth transition-metal dicarbides with a chiral crystal structure (space groups P41/P43). The project was focused on the determination of the structural and physical properties of these compounds at the enantiomorph resolution scale and on the study of the response of the magnetic properties of the Ce-based compound upon targeted iso- and non-isoelectronic substitutions in the R- (by La) and T- (by Co, Ir, Ru and Pd) sites. Anisotropy and handedness effects on the electrical transport, especially in the presence of a magnetic field, were of particular interest – beside the basic features - due to possible practically important properties. The combination of precise preparation, careful characterisation of the synthesised materials (in particular using state of the art metallographic techniques) with the fabrication of microdevices by focused ion beam technique is the unique feature of this project and bodes well for its originality. For the first time, EBSD-based precharacterisation of the sample material confirmed both enantiomorphs for LaRhC2, in full agreement with the results of single crystal X-ray structure determination. The semiconducting properties and anisotropy derived from electronic structure calculations are verified by electrical resistivity measurements on single crystalline enantiopure and crystallographically oriented microdevices. In contrast to semiconducting LaRhC2, CeRhC2 exhibits Kondo semimetal properties due to the smaller energy gap. The Ce-containing material showed properties derived from the localised nature of its 4f electronic state. For the first time, the TN of CeRhC2 was found to be independent of crystallographic direction and crystal handedness. Systematic studies of substitutions on the metals sites revealed either a complete suppression of the AFM ordering (Ce by La at x > ~0.5) or a significant decrease of the TN (in particular by substitution of Rh by T = Ru, Pd).

Publications

• Crystal, electronic and magnetic structures of a novel series of intergrowth carbometalates R4Co2C3 (R = Y, Gd, Tb). Dalton Transactions, 50(12), 4202-4209.
  Levytskyi, Volodymyr; Isnard, Olivier; Kremer, Reinhard K.; Babizhetskyy, Volodymyr; Fontaine, Bruno; Rocquefelte, Xavier; Halet, Jean-François & Gumeniuk, Roman
  
• New intermetallics R1+xZr1−xNi (R = Er–Tm, x ~ 0.5) with the TiNiSi type of structure. Intermetallics, 137, 107279.
  Babizhetskyy, Volodymyr; Köhler, Jürgen; Myakush, Oksana; Smetana, Volodymyr; Levytskyi, Volodymyr & Mudring, Anja-Verena
  
• Sc3Ir4Si13+x and Sc4Ir7Ge6 – the perovskite-related crystal structures. Zeitschrift für Kristallographie - Crystalline Materials, 236(11-12), 313-323.
  Levytskyi, Volodymyr; Wagler, Jörg; Hennig, Christoph; Feig, Manuel; Weigel, Tina; Leithe-Jasper, Andreas; Meyer, Dirk C. & Gumeniuk, Roman
  
• Valence fluctuations in the 3D + 3 modulated Yb3Co4Ge13 Remeika phase. Dalton Transactions, 50(38), 13580-13590.
  Feig, Manuel; Akselrud, Lev; Motylenko, Mykhaylo; Bobnar, Matej; Wagler, Jörg; Kvashnina, Kristina O.; Levytskyi, Volodymyr; Rafaja, David; Leithe-Jasper, Andreas & Gumeniuk, Roman
  
• Composition dependent polymorphism and superconductivity in Y3+x{Rh,Ir}4Ge13−x. Dalton Transactions, 51(12), 4734-4748.
  Feig, Manuel; Carrillo-Cabrera, Wilder; Bobnar, Matej; Simon, Paul; Curfs, Caroline; Levytskyi, Volodymyr; Tsirlin, Alexander A.; Leithe-Jasper, Andreas & Gumeniuk, Roman
  
• Crystal, electronic structure and physical properties of U3Rh4Ge13 and Th2Rh3Ge5. Journal of Alloys and Compounds, 911, 165017.
  Levytskyi, Volodymyr; Svanidze, Eteri; Leithe-Jasper, Andreas & Gumeniuk, Roman
  
• Superconductivity of structurally disordered Y5Ir6Sn18. Dalton Transactions, 51(26), 10036-10046.
  Levytskyi, Volodymyr; Carrillo-Cabrera, Wilder; Akselrud, Lev; Kundys, Bohdan; Leithe-Jasper, Andreas & Gumeniuk, Roman
  
• Magnetism, electrical and thermal transport in R2Ni5C3 (R = La-Nd, Sm, Gd, Tb). Journal of Alloys and Compounds, 969, 172411.
  Levytskyi, Volodymyr; Babizhetskyy, Volodymyr; Isnard, Olivier & Gumeniuk, Roman
  
• New carbide ErC: synthesis, crystal and electronic structure, magnetic properties. Coll. Abstr. XV Internat. Conf. Cryst. Chem. Intermet. Compds. (September 25–27, 2023), Lviv, Ukraine, 2023
  Levytskyi V., Babizhetskyy V., Kotur B., Svitlyk V., Hennig C. & Gumeniuk R.
  
• Thermoelectric properties and scattering mechanisms in natural PbS. Physical Review B, 107(19).
  Zuñiga-Puelles, Esteban; Levytskyi, Volodymyr; Özden, Ayberk; Gürel, Tanju; Bulut, Nebahat; Himcinschi, Cameliu; Sevik, Cem; Kortus, Jens & Gumeniuk, Roman
  
• Yb₃Rh₄Sn₁₃ : Two-gap superconductor with a complex Fermi surface. Physical Review B, 108(21).
  Gumeniuk, Roman; Levytskyi, Volodymyr; Kundys, Bohdan & Leithe-Jasper, Andreas
  
• Bulk physical properties and enantiomorph-resolved electrical transport of chiral narrow-band semiconductors RRhC2 (R = La, Ce). Book Abstr. Progr. 24th Internat. Conf. Solid Compd. Trans. Elements (June 17-21, 2024), Prague, Czechia, 2024
  Levytskyi V., Burkhardt U., König M., Svanidze E., Grin Y. & Gumeniuk R.
  
• Evolution of charge density wave order in continuous solid solutions Lu(Ni1-Co )C2. Journal of Alloys and Compounds, 980, 173631.
  Michor, Herwig; Roman, Marta; Reisinger, Lisa; Fritthum, Maria; Schmelzenbart, Jana; Vock, Alexander; Levytskyi, Volodymyr; Babizhetskyy, Volodymyr & Kotur, Bogdan
  
• Low-temperature physical properties of the ����2Ni5C3 (���� = La-Nd, Sm, Gd, Tb) “interstitial” carbides. Progr. Abs. 87th Ann. Conf. DPG and DPG Spring Meeting (March 17-22, 2024), Berlin, Germany, 2024
  Levytskyi V., Babizhetskyy V., Isnard O. & Gumeniuk R.
  
• Structural and magnetic properties of the chiral solid solution La1-xCexRhC2. Book Abstr. Progr. 24th Internat. Conf. Solid Compd. Trans. Elements (June 17-21, 2024), Prague, Czechia, 2024
  Levytskyi V., Burkhardt U., König M., Svanidze E., Grin Y. & Gumeniuk R.
  
• Low temperature thermoelectric properties of the chiral phases RRhC2 (R = Ce, La), 41st Internat. Conf. Thermoelectrics & 7th Asian Conf. Thermoelectrics (June 15-19, 2025), Sendai, Japan, 2025
  Burkhardt U., Levytskyi V., König M., Svanidze E., Grin Y. & Gumeniuk R.