Research/Sitter/MAGNDATA / 1.1.109_RbMnBr3.mcif

RbMnBr₃

MAGNDATA entry 1.1.109 · 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 ≤ 8.8 K (−264 °C)Colour: where that sits relative to 25 °C. Saturation: how much margin it has.

Structure · 11 properties

Magnetic group	C2mm1′(0,0,γ)000s
Point group	mm21′
Parent space group	P 63/m m c No. 194
Repeats every	2.8 cells along a (not a whole number: that's what incommensurate means)
Propagation	[0.357 0.357 0] 1k
Cell	a 7.462 · b 7.462 · c 6.543 Å · α 90° · β 90° · γ 120°
Transition	8.8 K (−264 °C)
Measured at	4.5 K
Magnetic ions	Mn
Largest moment component	3.3 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 C2mm1′(0,0,γ)000s →

Atom sites · 7 sites · CSV

site	element	x	y	z
Rb1_1	Rb	0.3333	0.6667	0.75
Rb1_2	Rb	0.6667	0.3333	0.25
Mn1	Mn	0	0	0
Br1_1	Br	0.16	0.32	0.25
Br1_2	Br	0.84	0.16	0.75
Br1_3	Br	0.84	0.68	0.75
Br1_4	Br	0.16	0.84	0.25

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. J. Glinka et al. AIP Conference Proceedings (1973) · doi:10.1063/1.2946987

Cite the original paper and MAGNDATA, not this mirror.

Original file

⬇ 1.1.109_RbMnBr3.mcif from MAGNDATA · entry page

sha256 of this copy: 8e704b1f598df3faebb0460231bd6828324c448a6665817d87ec3b8ee7430aa8
The mirror keeps the bytes Bilbao served, so the original should hash the same unless MAGNDATA has revised the entry since: shasum -a 256 1.1.109_RbMnBr3.mcif.