Electronic phenomena studied in the nordic countries

The H-T phase diagram of Ni3TeO6 with neutron diffraction on single crystals

Not scheduled

15m

Max IV Lund

Speaker

Mr Christopher Andersen (Christopher Røhl Andersen)

Description

Multiferroic compounds with the coexistence of magnetic and ferroelectric orders are well known from few transition metal oxides with perovskite crystal structures. Recently, a new family of multiferroic oxides with other crystal structures has been found: *M*$_3$TeO$_6$ (*M* = Co, Mn, Ni). Ni3TeO6 has shown interesting multiferroic behaviour with its non-centrosymmetric structure and collinear antiferromagnetic order. A field induced second order spin flop transition has formerly been reported with a non-hysteric colossal magneto-electric coupling. We have performed, for the first time, neutron diffraction measurements on Ni$_3$TeO$_6$ single crystals in high magnetic fields. The second order spin flop transition from earlier reports is not observed, but a different phase transition is found from a commensurate antiferromagnetic peak to an incommensurate peak. The *H*- *T* phase diagram is mapped and we observe a rise in the critical field close to 20 K, where the incommensurate peak also starts to drift. The present findings invite to a discussion of not only the magnetic system, but also the mechanism behind the multiferroicity and the magneto-electric coupling.