In this work we benefited from recent advances in tools for crystal-structure analysis that enabled us to describe an exotic nanoscale phenomenon in structural chemistry. The Mn0.60 Ni0.40 As sample of the Mn1-x Nix As solid solution, exhibits an incommensurate compositional modulation intimately coupled with positional modulations. The average structure is of the simple NiAs type, but in contrast to a normal solid solution, we observe that manganese and nickel segregate periodically at the nano-level into ordered MnAs and NiAs layers with thickness of 2-4 face-shared octahedra. The detailed description was obtained by combination of 3D electron diffraction, scanning transmission electron microscopy, and neutron diffraction. The distribution of the manganese and nickel layers is perfectly described by a modulation vector q=0.360(3) c*. Displacive modulations are observed for all elements as a consequence of the occupational modulation, and as a means to achieve acceptable Ni-As and Mn-As distances. This modulated evolution of magnetic MnAs and non-magnetic NiAs-layers with periodicity at approximately 10 Å level, may provide an avenue for spintronics.

Center for Materials Science and Nanotechnology Department of Chemistry University of Oslo P O Box 1033 Blindern 0315 Oslo Norway

Department for Neutron Materials Characterization Institute for Energy Technology PO Box 40 2027 Kjeller Norway

Institute of Physics Academy of Sciences of the Czech Republic v v i Na Slovance 2 18221 Prague Czech Republic

Laboratoire CRISMAT UMR 6508 CNRS ENSICAEN 6 bd du Maréchal Juin 14050 Caen Cedex 4 France

See more in PubMed

McConnell J. D. C., Heine V., Phys. Rev. B 1985, 31, 6140–6142. PubMed

Howard C. J., Carpenter M. A., Acta Crystallogr. Sect. B 2010, 66, 40–50. PubMed

Gillie L. J., Hadermann J., Pérez O., Martin C., Hervieu M., Suard E., J. Solid State Chem. 2004, 177, 3383–3391.

Norén L., Withers R. L., Berger R., J. Solid State Chem. 2000, 151, 260–266.

Boström M., Lidin S., J. Alloys Compd. 2004, 376, 49–57.

Lind H., Boström M., Petříček V., Lidin S., Acta Crystallogr. Sect. B 2003, 59, 720–729. PubMed

Piao S. Y., Palatinus L., Lidin S., Inorg. Chem. 2008, 47, 1079–1086. PubMed

Li C., Pramana S. S., Skinner S. J., Dalton Trans. 2019, 48, 1633–1646. PubMed

Fredrickson D. C., Lee S., Hoffmann R., Inorg. Chem. 2004, 43, 6159–6167. PubMed

Sato N., Ouchi H., Takagiwa Y., Kimura K., Chem. Mater. 2016, 28, 529–533.

Rohrer F. E., Lind H., Eriksson L., Larsson A.-K., Lidin S., Z. Kristallogr. - Cryst. Mater. 2001, 216, 190–198.

Palatinus L., Klementová M., Dřínek V., Jarošová M., Petříček V., Inorg. Chem. 2011, 50, 3743–3751. PubMed

Fjellvåg H., Kjekshus A., Andresen A., Ziéba A., J. Magn. Magn. Mater. 1986, 61, 61–80.

Gemmi M., Mugnaioli E., Gorelik T. E., Kolb U., Palatinus L., Boullay P., Hovmöller S., Abrahams J. P., ACS Cent. Sci. 2019, 5, 1315–1329. PubMed PMC

Steciuk G., Palatinus L., Rohlíček J., Ouhenia S., Chateigner D., Sci. Rep. 2019, 9, 9156. PubMed PMC

Alsén N., Geol. Foeren. Stockholm Foerh. 1925, 47, 19–72.

Wilson R., Kasper J., Acta Crystallogr. 1964, 17, 95–101.

Petříček V., Eigner V., Dušek M., Čejchan A., Z. Kristallogr. - Cryst. Mater. 2016, 231, 301–312.

Palatinus L., Petříček V., Corrêa C. A., Acta Crystallogr. Sect. A 2015, 71, 235–244. PubMed

Palatinus L., Corrêa C. A., Steciuk G., Jacob D., Roussel P., Boullay P., Klementová M., Gemmi M., Kopeček J., Domeneghetti M. C., Cámara F., Petříček V., Acta Crystallogr. Sect. B 2015, 71, 740–751. PubMed