Research/Sitter/MAGNDATA / 1.1.6_TbMnO3.mcif

TbMnO₃

MAGNDATA entry 1.1.6 · 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 ≤ 41 K (−232 °C)Colour: where that sits relative to 25 °C. Saturation: how much margin it has.

Structure · 11 properties

Magnetic group	Pbnm1′(0,β,0)s00s
Point group	mmm1′
Parent space group	P b n m No. 62
Repeats every	3.7 cells along b (not a whole number: that's what incommensurate means)
Propagation	[0 0.27 0] 1k
Cell	a 5.297 · b 5.831 · c 7.403 Å · α 90° · β 90° · γ 90°
Transition	41 K (−232 °C)
Measured at	35 K
Magnetic ions	Mn, Tb
Largest moment component	2.9 μ_B
Method	Phase I. Below 28K a second phase (phase II) exists with a cycloidal spin arrangement.

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 Pbnm1′(0,β,0)s00s →

Atom sites · 4 sites · CSV

site	element	x	y	z
Tb1	Tb	−0.028	0.072	0.25
Mn1	Mn	0.5	0	0
O1	O	0.097	0.46	0.25
O2	O	−0.296	0.337	0.056

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

M. Kenzelmann et al. PHYSICAL REVIEW LETTERS (2005) · doi:10.1103/PhysRevLett.95.087206

Cite the original paper and MAGNDATA, not this mirror.

Original file

⬇ 1.1.6_TbMnO3.mcif from MAGNDATA · entry page

sha256 of this copy: 2de27d2484f9637f8255cb51c20265cf4200f885a1e09e70d96f116c855732d9
The mirror keeps the bytes Bilbao served, so the original should hash the same unless MAGNDATA has revised the entry since: shasum -a 256 1.1.6_TbMnO3.mcif.