Weak itinerant magnetic phases of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>La</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi>Ni</mml:mi><mml:mn>7</mml:mn></mml:msub></mml:mrow></mml:math>

Abstract

The authors investigate the low-moment magnetic phases of La${}_{2}$Ni${}_{7}$ using neutron diffraction on single crystals. At intermediate temperatures, there are two incommensurate magnetic phases with the same temperature-dependent propagation vector, but different magnetic-moment directions. At low temperatures, the magnetic structure abruptly becomes a uniaxial commensurate antiferromagnet through a first-order transition. These properties make La${}_{2}$Ni${}_{7}$ an interesting candidate in the search for interesting phenomena such as superconductivity via suppressing weak magnetic order through pressure and/or chemical substitution.

Topics & Concepts