Research/Sitter/MAGNDATA / 1.1.118_ErNi2Ge2.mcif

ErNi₂Ge₂

MAGNDATA entry 1.1.118 · 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 ≤ 3.1 K (−270 °C)Colour: where that sits relative to 25 °C. Saturation: how much margin it has.

Structure · 11 properties

Magnetic group	I2/m111′(0,0,γ)0ss
Point group	2/m1′
Parent space group	I 4/m m m No. 139
Repeats every	1.32 cells along c (not a whole number: that's what incommensurate means)
Propagation	[0 0 0.757] 1k
Cell	a 4.039 · b 4.039 · c 9.803 Å · α 90° · β 90° · γ 90°
Transition	3.1 K (−270 °C)
Measured at	1.38 K
Magnetic ions	Er
Largest moment component	7.46 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 I2/m111′(0,0,γ)0ss →

Atom sites · 3 sites · CSV

site	element	y	z
Er1	Er	0	0
Ni1	Ni	0.5	0.25
Ge1	Ge	0	0.376

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

⬇ 1.1.118_ErNi2Ge2.mcif from MAGNDATA · entry page

sha256 of this copy: c1dbbfc22063eed520f410c7f9228f1ae1581416bc4045b5fdf691711f0c8cea
The mirror keeps the bytes Bilbao served, so the original should hash the same unless MAGNDATA has revised the entry since: shasum -a 256 1.1.118_ErNi2Ge2.mcif.