Research/Sitter/MAGNDATA / 1.1.122_NdMn2Ge2.mcif

NdMn₂Ge₂

MAGNDATA entry 1.1.122 · 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 ≤ 250 K (−23 °C)Colour: where that sits relative to 25 °C. Saturation: how much margin it has.

Structure · 11 properties

Magnetic group	Im2′m′(0,0,γ)s00
Point group	m′m2′
Parent space group	I 4/m m m No. 139
Repeats every	5.46 cells along c (not a whole number: that's what incommensurate means)
Propagation	[0 0 0.183] 1k
Cell	a 4.109 · b 4.109 · c 10.924 Å · α 90° · β 90° · γ 90°
Transition	250 K (−23 °C)
Measured at	150 K
Magnetic ions	Mn, Nd
Largest moment component	2.27 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 Im2′m′(0,0,γ)s00 →

Atom sites · 3 sites · CSV

site	element	y	z	m_a	m_b	m_c	\|m\| (μ_B)
Nd1	Nd	0	0
Mn1	Mn	0.5	0.25	−1.48	0	0	1.48
Ge1	Ge	0	0.386

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

R. Welter et al. Journal of AlAys and Compounds (1995) · doi:10.1016/0925-8388(94)01378-0

Cite the original paper and MAGNDATA, not this mirror.

Original file

⬇ 1.1.122_NdMn2Ge2.mcif from MAGNDATA · entry page

sha256 of this copy: 07a2091d2020a94f07eb720b436ce39fbf9d1b2997d90053dc352d383509e0f7
The mirror keeps the bytes Bilbao served, so the original should hash the same unless MAGNDATA has revised the entry since: shasum -a 256 1.1.122_NdMn2Ge2.mcif.