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H. Michor, M. Roman, L. Reisinger, M. Fritthum, D. Weichselbaum, S. Steiner, V. Levytskyy, V. Babizhetskyy, B.Ya. Kotur, B. Stöger:
"Crystal Growth and Studies of Charge Density Wave Physics in Quasi-1D Metals RNiC₂";
Talk: The International Conference on Solid Compounds of Transition Elements SCTE 2021, Wroclaw, Poland (invited); 2021-04-12 - 2021-04-15.

Ternary carbides RNiC₂ (R = La, ... Lu, Y) and RCoC₂ (R = Nd, .. Lu) crystallize in the non-centrosymmetric orthorhombic CeNiC₂-type structure, space group Amm2. These compounds attracted attention already for two decades, because of various interesting properties such as charge density wave (CDW) formation related to quasi-one-dimensional electronic features and Fermi surface nesting in RNiC₂ with R = Pr, ..., Lu, Y, and, finally, a complex interplay of CDW ordering and rare earth magnetism in RNiC₂ (see Ref. [1] for a review).
Here, we report on crystal growth, crystallographic characteristics explored via single crystal XRD, as well as on magnetic and electronic properties studied by a variety of techniques revealing orientation dependent, anisotropic features of RNiC₂ (R = Pr, Nd, Gd, Dy, Ho, Y) single crystals. Based on heat capacity, thermal expansion and electrical resistivity studies, we analyse the nature of multiple CDW transitions occurring in RNiC₂ crystals (e.g., orthorhombic to incommensurate CDW and incommensurate to commensurate CDW). We discuss their relations to electronic and crystal structure changes and, employing Clausius-Clapeyron and generalized Ehrenfest relations, we discuss resulting pressure and strain dependencies of these transitions as well as an expected elastic interaction between magnetic and CDW order parameters due to the spontaneous magneto-striction revealed by our thermal expansion studies.
[1] V. Babizhetskyy, B. Kotur, V. Levytskyy, H. Michor, Chapter 298: Alloy systems and compounds containing rare earth metals and carbon, in: J.-C.G. Bünzli, V.K. Pecharsky (Eds.), Handbook on the Physics and Chemistry of Rare Earths, Vol. 52, North-Holland, Amsterdam, pp. 1-263. (2017).

charge density wave, rare earth intermetallic carbides