Intertwined density waves in a metallic nickelate

The sought-after mechanism of metal-to-metal transition in the Ruddlesden-Popper phase La4Ni3O10 could be revealed after 25 years of research in a recent publication. Combining single crystal synchrotron X-ray and neutron diffraction, coupled charge and spin order superlattices could be observed in high quality single crystals grown with a HKZ furnace at 20 bar oxygen pressure at Argonne National Lab. The authors present models of intertwined charge-density and spin-density waves that reproduce the measurements and explain semi-quantitatively the unusual metal-to-metal transition at approx. 150 K.