Interplay Between Bonding, Magnetism and Superconductivity in Sr(Ni1−xCox)2P2 and Sr(Ni1−xRhx)2P2 Single Crystals

Title: Interplay Between Bonding, Magnetism and Superconductivity in Sr(Ni1−xCox)2P2 and Sr(Ni1−xRhx)2P2 Single Crystals
When: Wednesday, October 23, 2024, 12:30
Place: Department of Condensed Matter Physics, Faculty of Sciences, Module 3, Seminar Room (5th Floor)
Speaker: Juan Schmidt, Ames Laboratory, Iowa, USA.

Interplay between bonding, magnetism and superconductivity in Sr(Ni1−xCox)2P2 and Sr(Ni1−xRhx)2P2 single crystals J. Schmidt [1,2], A. Sapkota [2], C. L. Mueller [1,2], G. Gorgen-Lesseux [1,2], S. Xiao [3], T. J. Slade [2], R. A. Ribeiro [1,2], S.-W. Lee [3], S. L. Bud’ko [1,2], P. C. Canfield [1,2] [1] Department of Physics and Astronomy, Iowa State University, Ames, IA 50011, USA. [2] Ames National Laboratory, Iowa State University, Ames, IA 50011, USA. [3] Department of Material Science and Engineering and Institute of Material Science, University of Connecticut, Storrs, Connecticut 06269-3136, USA. Bond formation and bond breaking in crystalline intermetallic solids can strongly impact other properties associated to delocalized electrons, such as itinerant magnetism and superconductivity. This has been observed on numerous occasions in materials with collapsed tetragonal transitions [1,2,3]. Although SrNi2P2 adopts the common ThCr2Si2 structure for T ≥ 325 K, being in an uncollapsed tetragonal (ucT) state, it is a special case for the ThCr2Si2 class: on cooling below 325 K it adopts a one-third collapsed orthorhombic (tcO) phase where one out of every three P-rows bond across the Sr layers [4,5]. It is also known for exhibiting bulk superconductivity at 1.4 K at ambient pressure, and no magnetic ordering down to 50 mK [4,6]. We find that substituting Ni with either Co or Rh causes a rapid decrease of the one-third collapse transition temperature, as well as alter either the magnetic or the superconducting properties of the pure compound. On one hand, Co substitution levels above 50% serve to stabilize antiferromagnetic and ferromagnetic orderings [5]. On the other hand, when substituting with Rh, an enhancement of the superconducting transition temperature is observed immediately after the suppression of the collapse transition.

 
References

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