Research/Sitter/MAGNDATA / 1.1.21_Li2IrO3.mcif

Li₂IrO₃

MAGNDATA entry 1.1.21 · 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 ≤ 39.5 K (−234 °C)Colour: where that sits relative to 25 °C. Saturation: how much margin it has.

Structure · 10 properties

Magnetic group	C2221′(α00)s00s
Point group	2221′
Parent space group	C c c m No. 66
Repeats every	1.75 cells along a (not a whole number: that's what incommensurate means)
Propagation	[0.57 0 0] 1k
Cell	a 5.9119 · b 8.4461 · c 17.8363 Å · α 90° · β 90° · γ 90°
Transition	39.5 K (−234 °C)
Magnetic ions	Ir
Largest moment component	1 μ_B
Method	MRXD

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 C2221′(α00)s00s →

Atom sites · 19 sites · CSV

site	element	x	y	z
Ir1_1	Ir	0.25	0.25	0.0836
Ir1_2	Ir	−0.25	−0.25	−0.0836
Ir2_1	Ir	0.5	0.5	0.167
Ir2_2	Ir	−0.5	−0.5	−0.167
Li1_1	Li	0	0.5	0.3333
Li1_2	Li	0	−0.5	−0.3333
Li2_1	Li	0.75	0.25	0.25
Li2_2	Li	−0.75	−0.25	−0.25
Li3_1	Li	0.75	0.25	0.9167
Li3_2	Li	−0.75	−0.25	−0.9167
Li4	Li	0.5	0.5	0.5
Li5	Li	0.5	0	0
O1_1	O	0.77	0.515	0.087
O1_2	O	−0.77	−0.515	−0.087
O2_1	O	0.72	0.5	0.25
O2_2	O	−0.72	−0.5	−0.25
O3	O	0	0.262	0
O4_1	O	0.49	0.262	0.163
O4_2	O	−0.49	−0.262	−0.163

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

A. Biffin et al. PHYSICAL REVIEW LETTERS (2014) · doi:10.1103/PhysRevLett.113.197201

Cite the original paper and MAGNDATA, not this mirror.

Original file

⬇ 1.1.21_Li2IrO3.mcif from MAGNDATA · entry page

sha256 of this copy: 313c7324a7b2812af0c8def5e9f222a0ef79de0935f9b53fe449cb1351695b24
The mirror keeps the bytes Bilbao served, so the original should hash the same unless MAGNDATA has revised the entry since: shasum -a 256 1.1.21_Li2IrO3.mcif.