Research/Sitter/MAGNDATA / 1.1.119_HoNi2Ge2.mcif

HoNi₂Ge₂

MAGNDATA entry 1.1.119 · source

incommensurate spin-density wave

Incommensurate: the magnetic pattern repeats every so many cells, but not a whole number of them, so it never lines up with the crystal lattice. Here it's a spin-density wave: the size of the spin swells and shrinks as you move along.

ordered ≤ 4.1 K (−269 °C)Colour: where that sits relative to 25 °C. Saturation: how much margin it has.

Structure · 11 properties

Magnetic group	I11′(α,β,γ)0s
Point group	11′
Parent space group	I 4/m m m No. 139
Repeats every	1.27 cells along c (not a whole number: that's what incommensurate means)
Propagation	[0.014 0.073 0.785] 1k
Cell	a 4.029 · b 4.029 · c 9.78 Å · α 90° · β 90° · γ 90°
Transition	4.1 K (−269 °C)
Measured at	1.46 K
Magnetic ions	Ho
Largest moment component	7.4 μ_B
Method	NPD

Symmetry

Stereogram of the magnetic point group: each operation applied to one direction. Filled = upper hemisphere, ring = lower; red operations include time reversal. Lines are mirrors; polygons are 2/3/4/6-fold axes; the centre ring is inversion.

Every structure in I11′(α,β,γ)0s →

Atom sites · 3 sites · CSV

site	element	x	z
Ho1	Ho	0	0
Ni1	Ni	0.5	0.75
Ge1	Ge	0	0.377

Incommensurate: the moments are modulated; the picture evaluates each atom's Fourier series at its own phase.

Moment components are along the crystal axes a, b, c (μ_B), as magCIF writes them. Symmetry generates the rest of the cell from these sites.

Source

G. Andre et al. Journal of Alloys and Compounds (1995) · doi:10.1016/0925-8388(95)01545-0

Cite the original paper and MAGNDATA, not this mirror.

Original file

⬇ 1.1.119_HoNi2Ge2.mcif from MAGNDATA · entry page

sha256 of this copy: 4bc3cf67e79cd417d4289697fc60ba5ac14a31c2091aec065dcdc2003363ffe9
The mirror keeps the bytes Bilbao served, so the original should hash the same unless MAGNDATA has revised the entry since: shasum -a 256 1.1.119_HoNi2Ge2.mcif.