Research/Sitter/MAGNDATA / 1.1.99_KAg2Fe(VO4)2.mcif

KAg₂Fe(VO₄)₂

MAGNDATA entry 1.1.99 · 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 ≤ 2.8 K (−270 °C)Colour: where that sits relative to 25 °C. Saturation: how much margin it has.

Structure · 11 properties

Magnetic group	P31′(1/3,1/3,γ)ts
Point group	31′
Parent space group	P 3 No. 147
Repeats every	2.48 cells along c (not a whole number: that's what incommensurate means)
Propagation	[0.33333 0.33333 0.4035] 1k
Cell	a 5.4811 · b 5.4811 · c 7.2119 Å · α 90° · β 90° · γ 120°
Transition	2.8 K (−270 °C)
Measured at	1.5 K
Magnetic ions	Fe
Largest moment component	3.4641 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 P31′(1/3,1/3,γ)ts →

Atom sites · 10 sites · CSV

site	element	x	y	z
Ag1_1	Ag	0.3333	0.6667	0.296
Ag1_2	Ag	0.6667	0.3333	0.704
K1_1	K	0	0	0
Fe1_1	Fe	0	0	0.5
V1_1	V	0.3333	0.6667	0.729
V1_2	V	0.6667	0.3333	0.271
O1_1	O	0.666	−0.099	0.663
O1_2	O	0.334	0.099	0.337
O2_1	O	0.3333	0.6667	−0.035
O2_2	O	0.6667	0.3333	0.035

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

N. E. Amuneke et al. Chem. Mater. (2014) · doi:10.1021/cm5025712

Cite the original paper and MAGNDATA, not this mirror.

Original file

⬇ 1.1.99_KAg2Fe(VO4)2.mcif from MAGNDATA · entry page

sha256 of this copy: 075d075d003bde2ae1aefb1de67fc184e0806886c4242ad6c5c65d68af044433
The mirror keeps the bytes Bilbao served, so the original should hash the same unless MAGNDATA has revised the entry since: shasum -a 256 1.1.99_KAg2Fe(VO4)2.mcif.