Research/Sitter/MAGNDATA / 1.1.93_Ca0.93Sr0.07BaCo4O7.mcif

Ca_0.93Sr_0.07BaCo₄O₇

MAGNDATA entry 1.1.93 · 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 ≤ 82 K (−191 °C)Colour: where that sits relative to 25 °C. Saturation: how much margin it has.

Structure · 11 properties

Magnetic group	Pna2₁1′(1/2,1/2,γ)qq0s
Point group	mm21′
Parent space group	Pna2₁ No. 33
Repeats every	2 cells along a (not a whole number: that's what incommensurate means)
Propagation	[0.5 0.5 0.0197] 1k
Cell	a 11.03519 · b 6.26586 · c 10.17849 Å · α 90° · β 90° · γ 90°
Transition	82 K (−191 °C)
Measured at	70 K
Magnetic ions	Co
Largest moment component	2.39 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 Pna2₁1′(1/2,1/2,γ)qq0s →

Atom sites · 14 sites · CSV

site	element	x	y	z
Ca1	Ca	0.6717	0.5053	0.1279
Sr1	Sr	0.6717	0.5053	0.1279
Ba1	Ba	0.6654	0.5039	0.5
Co1	Co	0	0.5081	0.0575
Co2	Co	0.1717	0.5	0.3123
Co3	Co	0.0866	0.7448	0.8101
Co4	Co	−0.0824	0.7694	0.3195
O1	O	0.0002	0.5	0.7477
O2	O	0.4925	0.5	0.7701
O3	O	0.2609	0.2872	0.2185
O4	O	0.7434	0.2304	0.7916
O5	O	0.1522	0.5	0.4991
O6	O	0.109	0.7058	−0.0018
O7	O	−0.0521	0.7636	0.5041

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

J. Lohr et al. PHYSICAL REVIEW B (2020) · doi:10.1103/PhysRevB.102.134406

Cite the original paper and MAGNDATA, not this mirror.

Original file

⬇ 1.1.93_Ca0.93Sr0.07BaCo4O7.mcif from MAGNDATA · entry page

sha256 of this copy: 19539f111e55215931f2ad4eac16747cca1de583aa205382061c25329205953b
The mirror keeps the bytes Bilbao served, so the original should hash the same unless MAGNDATA has revised the entry since: shasum -a 256 1.1.93_Ca0.93Sr0.07BaCo4O7.mcif.