Research/Sitter/MAGNDATA / 1.1.39_Ca3Co2O6.mcif

Ca₃Co₂O₆

MAGNDATA entry 1.1.39 · 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 ≤ 25 K (−248 °C)Colour: where that sits relative to 25 °C. Saturation: how much margin it has.

Structure · 11 properties

Magnetic group	R3c1′(00γ)00s
Point group	3m1′
Parent space group	R 3c No. 167
Repeats every	0.98 cells along c (not a whole number: that's what incommensurate means)
Propagation	[0 0 1.02] 1k
Cell	a 9.0729 · b 9.0729 · c 10.3759 Å · α 90° · β 90° · γ 120°
Transition	25 K (−248 °C)
Measured at	20 K
Magnetic ions	Co
Largest moment component	5 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 R3c1′(00γ)00s →

Atom sites · 4 sites · CSV

site	element	x	y	z
Ca1	Ca	0.3694	0	0.25
Co1	Co	0	0	0
Co2	Co	0	0	0.25
O1	O	0.1768	0.0246	0.1138

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. Agrestini et al. Phys. (2008) · doi:10.1103/PhysRevLett.101.097207

Cite the original paper and MAGNDATA, not this mirror.

Original file

⬇ 1.1.39_Ca3Co2O6.mcif from MAGNDATA · entry page

sha256 of this copy: 5b87a28ed8965effa667442ac1afadcf27b4bf13e12e7fdfbe8f414beabbaa46
The mirror keeps the bytes Bilbao served, so the original should hash the same unless MAGNDATA has revised the entry since: shasum -a 256 1.1.39_Ca3Co2O6.mcif.