Field-induced magnetic phases and electric polarization in LiNiPO4

TitleField-induced magnetic phases and electric polarization in LiNiPO4
Publication TypeJournal Article
Year of Publication2009
AuthorsJensen TBS, Christensen NB, Kenzelmann M, Ronnow HM, Niedermayer C, Andersen NH, Lefmann K, Schefer J, Von Zimmermann M, Li J, Zarestky JL, Vaknin D
Journal TitlePhysical Review B
Date Published03/01
ISBN Number1098-0121
Accession NumberISI:000264768200015
Keywordsantiferromagnetism, ferroelectricity, licopo4, lithium compounds, magnetic structure, magnetic transitions, magnetoelastic effects, magnetoelectric effects, multiferroics, neutron diffraction, nickel compounds

Neutron diffraction is used to probe the (H,T) phase diagram of magnetoelectric (ME) LiNiPO4 for magnetic fields along the c axis. At zero field the Ni spins order in two antiferromagnetic phases. One has commensurate (C) structures and general ordering vectors k(C)=(0,0,0); the other one is incommensurate (IC) with k(IC)=(0,q,0). At low temperatures the C order collapses above mu H-0=12 T and adopts an IC structure with modulation vector parallel to k(IC). We show that C order is required for the ME effect and establish how electric polarization results from a field-induced reduction in the total magnetoelastic energy.

URL<Go to ISI>://000264768200015