Research/Sitter/MAGNDATA / 1.1.73_Tb2Ni3Si5.mcif

Tb₂Ni₃Si₅

MAGNDATA entry 1.1.73 · 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 ≤ 19.5 K (−254 °C)Colour: where that sits relative to 25 °C. Saturation: how much margin it has.

Structure · 11 properties

Magnetic group	Ibam1′(00γ)000s
Point group	mmm1′
Parent space group	I b a m No. 72
Repeats every	1.26 cells along c (not a whole number: that's what incommensurate means)
Propagation	[0 0 0.794] 1k
Cell	a 9.544 · b 11.136 · c 5.6286 Å · α 90° · β 90° · γ 90°
Transition	19.5 K (−254 °C)
Measured at	13 K
Magnetic ions	Tb
Largest moment component	6.55 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 Ibam1′(00γ)000s →

Atom sites · 6 sites · CSV

site	element	x	y	z
Tb1	Tb	0.2682	0.373	0
Ni1	Ni	0.1148	0.139	0
Ni2	Ni	0.5	0	0.25
Si1	Si	0.3467	0.131	0
Si2	Si	0	0.261	0.25
Si3	Si	0	0	0.25

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. Szytula et al. J. Phys.: Condens. Matter (1997) · doi:10.1088/0953-8984/9/31/017

Cite the original paper and MAGNDATA, not this mirror.

Original file

⬇ 1.1.73_Tb2Ni3Si5.mcif from MAGNDATA · entry page

sha256 of this copy: 0427d077ee19e6aadd920a12e72b5cec1f5c3c451675f7c48f068ddf5282d414
The mirror keeps the bytes Bilbao served, so the original should hash the same unless MAGNDATA has revised the entry since: shasum -a 256 1.1.73_Tb2Ni3Si5.mcif.