Crystal and Magnetic Structures of the Ternary Ho2Ni0.8Si1.2 and Ho2Ni0.8Ge1.2 Compounds: An Example of Intermetallics Crystallizing with the Zr2Ni1- xP Prototype

Alessia Provino; Clemens Ritter; Volodymyr Smetana; Anja-Verena Mudring; Marcella Pani; Vitalij K Pecharsky; Pietro Manfrinetti

doi:10.1021/acs.inorgchem.1c02211

Crystal and Magnetic Structures of the Ternary Ho₂Ni_0.8Si_1.2 and Ho₂Ni_0.8Ge_1.2 Compounds: An Example of Intermetallics Crystallizing with the Zr₂Ni_{1- x}P Prototype

Inorg Chem. 2021 Nov 1;60(21):16397-16408. doi: 10.1021/acs.inorgchem.1c02211. Epub 2021 Oct 15.

Authors

Alessia Provino^{1

2}, Clemens Ritter³, Volodymyr Smetana⁴, Anja-Verena Mudring⁴, Marcella Pani^{1

5}, Vitalij K Pecharsky^{2

6}, Pietro Manfrinetti^{1

2

5}

Affiliations

¹ Department of Chemistry, University of Genova, 16146 Genova, Italy.
² The Ames Laboratory, U.S. Department of Energy, Iowa State University, Ames, Iowa 50011-3020, United States.
³ Institut Laue-Langevin (ILL), 38042 Grenoble, France.
⁴ Department of Materials and Environmental Chemistry, Stockholm University, 10691 Stockholm, Sweden.
⁵ Institute SPIN-CNR, 16152 Genova, Italy.
⁶ Department of Materials Sciences and Engineering, Iowa State University, Ames, Iowa 50011-2300, United States.

Abstract

We report two new rare-earth (R) ternary intermetallic compounds-Ho₂Ni_0.8T_1.2 with T = Si and Ge-that correspond to the R₅Ni₂T₃ phase earlier reported to form in Dy-Ni-T and Ho-Ni-T ternary systems. The compounds crystallize in a filled version of the orthorhombic Zr₂Ni_1-xP-type structure with x = 0.52; their stoichiometry, determined from both single-crystal and powder X-ray diffraction data, is centered on Ho₂Ni_0.8T_1.2 with a narrow solid solubility range for the silicide, while the germanide appears to be a line phase. In addition to R = Dy and Ho, R₂Ni_0.8T_1.2 compounds also form for R = Y and Tb, representing the first examples of rare-earth-based compounds adopting the Zr₂Ni_1-xP structural prototype. Bulk magnetization data reveal the main transitions of the ferrimagnetic or ferromagnetic type at T_C = 38 K for Ho₂Ni_0.8Si_1.2 and T_C = 37 K for Ho₂Ni_0.8Ge_1.2, which are followed by subsequent magnetic reordering at lower temperatures. Neutron diffraction shows complex magnetic structures below T_C with both ferromagnetic and antiferromagnetic components and magnetic propagation vector κ₁ = [0, 0, 0]. Below T_N ≅ 24 K (22 K) for the silicide (germanide), an additional antiferromagnetic coupling following an incommensurate magnetic propagation vector κ₂ = [κ_x, 0, 0] appears to coexist with the first magnetic structure.