Research/Sitter/MAGNDATA / 1.1.120_Er3Cu4Sn4.mcif

Er₃Cu₄Sn₄

MAGNDATA entry 1.1.120 · 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 ≤ 2 K (−271 °C)Colour: where that sits relative to 25 °C. Saturation: how much margin it has.

Structure · 11 properties

Magnetic group	C2/m1′_c(0,β,0)s00
Point group	2/m1′
Parent space group	C 2/m No. 12
Repeats every	1.88 cells along b (not a whole number: that's what incommensurate means)
Propagation	[0 0.5333 0] 2k
Cell	a 16.0831 · b 4.3887 · c 13.7464 Å · α 90° · β 115.754° · γ 90°
Transition	2 K (−271 °C)
Measured at	1.4 K
Magnetic ions	Er
Largest moment component	9.6 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 C2/m1′_c(0,β,0)s00 →

Atom sites · 6 sites · CSV

site	element	x	z	m_a	m_b	m_c	\|m\| (μ_B)
Er1	Er	0	0.25	0	8.91	0	8.91
Er2	Er	0.13	0.0595
Cu1	Cu	0.322	0.2575
Cu2	Cu	0.338	0.078
Sn1	Sn	0.216	0.364
Sn2	Sn	0.507	0.1055

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

S. Baran et al. Acta Cryst. B (2021) · doi:10.1107/S205252062100127X

Cite the original paper and MAGNDATA, not this mirror.

Original file

⬇ 1.1.120_Er3Cu4Sn4.mcif from MAGNDATA · entry page

sha256 of this copy: 0d652154e6a624fc6374ffc320a064a2440f7f347cda56bbc9825fe12bbc9ea3
The mirror keeps the bytes Bilbao served, so the original should hash the same unless MAGNDATA has revised the entry since: shasum -a 256 1.1.120_Er3Cu4Sn4.mcif.