Analyzing 3-D neutron polarization under high pressure

December 20, 2018, National Institute for Materials Science
(Left) Completely nonmagnetic hybrid anvil cell developed for three-dimensional neutron polarization analysis. (Right) Magnetic and dielectric phase diagram in relation to temperature and pressure applied to delafossite (CuFeO2), which was found to transform into a ferroelectric and multiferroic material under high pressure Credit: NIMS

A joint research team consisting of NIMS, JAEA and the Institut Laue Langevin has developed a high-pressure cell composed of completely nonmagnetic materials. The team then succeeded for the first time in analyzing neutron polarization in three dimensions at an extremely high pressure of several gigapascals using the cell. This technique is applicable to detailed analysis of electron spin arrangements. The team also discovered a material with potential as a next-generation PC memory material due to the multiferroic properties it exhibited under high pressure. The technique may be used to understand pressure-induced changes in electron spin arrangements in various materials and to develop new materials by controlling spins.

Electron spins fundamentally determine the magnetic properties of materials. Recent research focusing on controlling electron spins has led to the development of new functional materials, including multiferroic materials. The use of neutron diffraction techniques, which enable observation of spin arrangements in materials, is indispensable in these material development efforts. Three-dimensional neutron polarization analysis is particularly effective in determining precise spin arrangements while controlling three-dimensional neutron spin orientations. However, use of this technique requires a cell in which a sample material can be kept in a completely nonmagnetic state in order to preserve the degree of neutron spin polarization specific to the sample. Conventional high-pressure are unsuitable for use in this analysis because they are composed of magnetic materials that generate magnetic flux.

In this research, the NIMS-led team developed a completely nonmagnetic cell by replacing conventional magnetic cell materials with nonmagnetic composite materials made of diamond particles. The team then confirmed that use of the newly developed cell does not reduce the degree of spin polarization in a sample material. The team also discovered a material that is non-ferroelectric at normal atmospheric pressure in a nonmagnetic environment but becomes ferroelectric and multiferroic when subjected to several tens of thousands of atmospheres of pressure.

The technique developed in this research may be applied to the development not only of materials but also of superconducting and other functional whose functionalities are closely related to spin arrangements.

Explore further: World's first observation of spin arrangements using neutron transmission

More information: Noriki Terada et al, Spherical neutron polarimetry under high pressure for a multiferroic delafossite ferrite, Nature Communications (2018). DOI: 10.1038/s41467-018-06737-6

Related Stories

Neutrons scan magnetic fields inside samples

October 5, 2018

With a newly developed neutron tomography technique, an HZB team has mapped for the first time magnetic field lines inside materials at the BER II research reactor. Tensorial neutron tomography promises new insights into ...

Precise electron spin control yields faster memory storage

October 9, 2018

Data storage devices are not improving as fast as scientists would like. Faster and more compact memory storage devices will become a reality when physicists gain precise control of the spins of electrons. They typically ...

Neutrons help demystify multiferroic materials

March 19, 2018

Materials used in electronic devices are typically chosen because they possess either special magnetic or special electrical properties. However, an international team of researchers using neutron scattering recently identified ...

Recommended for you

Rapid and continuous 3-D printing with light

January 22, 2019

Three-dimensional (3-D) printing, also known as additive manufacturing (AM), can transform a material layer by layer to build an object of interest. 3-D printing is not a new concept, since stereolithography printers have ...

Scientists discover new quantum spin liquid

January 22, 2019

An international research team led by the University of Liverpool and McMaster University has made a significant breakthrough in the search for new states of matter.

Researchers capture an image of negative capacitance in action

January 21, 2019

For the first time ever, an international team of researchers imaged the microscopic state of negative capacitance. This novel result provides researchers with fundamental, atomistic insight into the physics of negative capacitance, ...

Toward ultrafast spintronics

January 21, 2019

Electronics have advanced through continuous improvements in microprocessor technology since the 1960s. However, this process of refinement is projected to stall in the near future due to constraints imposed by the laws of ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.