Electric field control of chiral magnetic domains in the high-temperature multiferroic CuO
Physical Review B - Condensed Matter and Materials Physics 85:13 (2012)
Abstract:
We have studied the high-temperature multiferroic cupric oxide using polarized neutron diffraction as a function of temperature and applied electric field. We find that the chiral domain population can be varied using an external electric field applied along the b axis. With the aid of representation analysis, we deduce the incommensurate magnetic structure in the multiferroic phase. We conclude that the origin of the magnetoelectric coupling is consistent with recently proposed models which are based on the inverse Dzyaloshinskii - Moriya interaction. 漏 2012 American Physical Society.Helical scattering signatures of strain and electronic textures in YbFe 2 O 4 from three-dimensional reciprocal-space imaging
Physical Review B - Condensed Matter and Materials Physics 85:1 (2012)
Abstract:
The insulating ternary oxide YbFe 2O 4 displays an unusual frustration-driven incommensurate charge-ordering (CO) transition, linked to possible ferroelectricity. Based on high-resolution synchrotron data, we report a detailed structural model showing that the CO phase is an incommensurate charge-density wave and cannot be ferroelectric, since the electrical dipole moments are also incommensurately modulated. The change between continuous and "spotty" helices of scattering at the CO transition is attributed to three-dimensional fluctuations of the direction of the ordering wave vector. 漏 2012 American Physical Society.Evidence of magnetic correlations among the charge stripe electrons of charge-stripe ordered La2 NiO4.11
Journal of Physics: Conference Series 340 (2012)
Abstract:
The magnetic excitations of charge-stripe ordered La2NiO 4.11 where investigated using polarized- and unpolarized-neutron scattering to determine the magnetic excitations of the charge stripe electrons. We observed a magnetic excitation mode consistent with the gapped quasi-one-dimensional antiferromagnetic correlations of the charge stripe electrons previously observed in La2-xSrxNiO4 x = 1/3 and x = 0.275.Search for third harmonic magnetic Bragg reflections in charge-stripe ordered La1.725 Sr0.275 NiO4
Journal of Physics: Conference Series 391:1 (2012)
Abstract:
The magnetic Bragg reflections of charge-stripe ordered La1.725Sr0.275NiO4 where investigated by neutron diffraction to determine the intensity ratio of first to third order harmonics. The third harmonic Bragg reflections were not observed at temperatures across that magnetically ordered phase, creating an upper bound for their intensity of 0.16% of the first harmonic intensity. 漏 Published under licence by IOP Publishing Ltd.Electric field control of the magnetic chiralities in ferroaxial multiferroic RbFe(MoO4)2
arXiv [cond-mat.str-el] (2012) 1202.2317