Research/Sitter/MAGNDATA / 1.1.85_CuBr2.mcif

CuBr₂

MAGNDATA entry 1.1.85 · source

incommensurate spiral

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 spiral: the spin direction rotates as you move along.

ordered ≤ 74 K (−199 °C)Colour: where that sits relative to 25 °C. Saturation: how much margin it has.

Structure · 11 properties

Magnetic group	Cm1′(0β1/2)0s
Point group	m1′
Parent space group	C 2/m No. 12
Repeats every	1.31 cells along b (not a whole number: that's what incommensurate means)
Propagation	[0 0.765 0.5] 1k
Cell	a 7.2096 · b 3.4742 · c 7.0475 Å · α 90° · β 119.61° · γ 90°
Transition	74 K (−199 °C)
Measured at	1.8 K
Magnetic ions	Cu
Largest moment component	0.41 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 Cm1′(0β1/2)0s →

Atom sites · 3 sites · CSV

site	element	x	y	z
Cu1	Cu	0	0	0
Br1_1	Br	0.2288	0.5	0.2389
Br1_2	Br	−0.2288	0.5	−0.2389

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

C. Lee et al. PHYSICAL REVIEW B (2012) · doi:10.1103/PhysRevB.86.060407

Cite the original paper and MAGNDATA, not this mirror.

Original file

⬇ 1.1.85_CuBr2.mcif from MAGNDATA · entry page

sha256 of this copy: d71be64cf145dd8a130fc110b0268e975e856942f08514f1ef889488a5ea0ee8
The mirror keeps the bytes Bilbao served, so the original should hash the same unless MAGNDATA has revised the entry since: shasum -a 256 1.1.85_CuBr2.mcif.