15-18 March 2021
Europe/Berlin timezone

First order CDW phase transitions in R2Ir3Si5 (R = Ho, Er, Lu)

15 Mar 2021, 15:45



Sander van Smaalen (University of Bayreuth)


R$_2$Ir$_3$Si$_5$ (R = Ho, Er, Lu) crystallize in the U$_2$Co$_3$Si$_5$ structure type at room temperature (orthorhombic space group Ibam) [1]. Upon cooling they undergo first-order charge-density-wave (CDW) phase transitions, as evidenced by anomalies with hysteresis in the temperature dependencies of the electrical resistivity ($\rho$), specific heat ($C_p$), magnetic susceptibility ($\chi$), Seebeck coefficient ($S$) and thermal conductivity ($\kappa$) [1-4]. The CDW character of the low-temperature phases is corroborated by the appearance of satellite reflections at q = (0.2495, 0.4973, 0.2483) in diffraction experiments [4,5]. Single-crystal x-ray diffraction has revealed that the incommensurate CDW is accompanied by a strong monoclinic lattice distortion, while the symmetry of the CDW phase is reduced to triclinic. Here, we discuss the microscopic mechanism of CDW formation on the basis of a superspace analysis of single-crystal x-ray diffraction data [4].

Acknowledgement: Single-crystal X-ray diffraction data were collected at Beamline P24 of PETRA-III at DESY, Hamburg, Germany.

[1] Y. Singh, D. Pal, S. Ramakrishnan, A. M. Awasthi and S. K. Malik, Phys. Rev. B 71, 045109 (2005).
[2] Y. K. Kuo, K. M. Sivakumar, T. H. Su and C. S. Lue, Phys. Rev. B 74, 045115 (2006).
[3] N. S. Sangeetha, A. Thamizhavel, C. V. Tomy, S. Basu, A. M. Awasthi, P. Rajak, S. Bhattacharyya, S. Ramakrishnan and D. Pal, Phys. Rev. B 91, 205131 (2015).
[4] S. Ramakrishnan, A. Schonleber, T. Rekis, N. van Well, L. Noohinejad, S. van Smaalen, M. Tolkiehn, C. Paulmann, B. Bag, A. Thamizhavel, D. Pal and S. Ramakrishnan, Phys. Rev. B 101, 060101(R) (2020).
[5] M. H. Lee, C. H. Chen, M. -W. Chu, C. S. Lue and Y. K. Kuo, Phys. Rev. B 83, 155121 (2011).

Primary authors

Sander van Smaalen (University of Bayreuth) Dr Sitaram Ramakrishnan (Laboratory of Crystallography, University of Bayreuth, 95447 Bayreuth, Germany) Dr Andreas Schönleber (University of Bayreuth) Jinke Bao (University of Bayreuth) Mr Claudio Eisele (Laboratory of Crystallography, University of Bayreuth, 95447 Bayreuth, Germany) Mr Surya Rohith Kotla (Laboratory of Crystallography, University of Bayreuth, 95447 Bayreuth, Germany) Mr Achim M. Schaller (University of Bayreuth) Toms Rekis (University of Bayreuth) Prof. Natalija van Well (Ludwig-Maximilians-University Munich) Dr Biplab Bag (Tata Institute of Fundamental Research, Mumbai) Prof. Arumugam Thamizhavel (Tata Institute of Fundamental Research, Mumbai ) Prof. Srinivasan Ramakrishnan (Tata Institute of Fundamental Research, Mumbai) Dr Dilip Pal (Indian Institute of Technology, Guwahati) Dr Nediyedath S. Sangeetha (Indian Institute of Technology, Guwahati ) Dr Leila Noohinejad (DESY) Dr Martin Tolkiehn (DESY) Dr Carsten Paulmann (DESY)

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