A. Kikkawa

Field-induced Incommensurate Lattice Modulations in the Delafossite CuFeO2

The results of synchrotron X-ray diffraction measurements on a single crystal of the triangular lattice antiferromagnet CuFeO 2 under zero and non-zero applied magnetic fields are reported. We find four satellite reflections at (0, 3+ q , 1/2), (0, 4- q , 1/2), (0, 4-2 q , 0), and (0, 3+2 q , 0) with the incommensurate wave number q ∼0.415 in the ferroelectric incommensurate (FEIC) phase which appears in the magnetic field, H , between 7 and 13 T at low temperatures. In the partially disordered (PD) phase which exists in the temperature, T , range between 11 and 14 K, we find two satellite reflections at (0, 4- q , 1/2) and (0, 4-2 q , 0) with the incommensurate wave number q ∼0.4. The T and H dependence of these satellite reflections are studied. We interpret that the reflections observed in the FEIC phase arise from incommensurate lattice modulations caused by a magnetoelastic coupling with the underlying magnetic structure. The observation of the reflection (0, 4- q , 1/2) in finite fields and the (0, ...

Low Temperature Magnetic Properties of Ce3Pd20Si6

Magnetization of a single crystalline Ce 3 Pd 20 Si 6 was measured at low temperatures down to 90 mK in fields up to 11 T for the three principal directions [100], [110], and [111]. For all directions, two transitions were observed in the temperature variation of the magnetization M ( T ) at 0.2 T; a broad peak at 0.28 K associated with a phase-III transition, and an upward bending at ∼0.5 K due to a phase-II ordering from the paramagnetic state (phase-I). The latter critical temperature T I–II is found to be strongly enhanced in magnetic fields B , depending on the field direction, and T I–II ( B ) becomes highly anisotropic. These results suggest that phase-II is an antiferroquadrupole state originated from a Γ 8 ground state. By contrast, no appreciable anisotropy is found in the phase-III state. At 90 mK, phase-III collapses by applying a field of ∼0.63 T for all directions. Above this field, the magnetization curve M ( B ) becomes strongly anisotropic. The magnetization value per Ce in the phase-I re...

Lattice Deformations Induced by an Applied Magnetic Field in the Frustrated Antiferromagnet HgCr2O4

The way geometric frustration in the pyrochlore antiferromagnet HgCr 2 O 4 is relieved by an applied magnetic field is studied by synchrotron X-ray diffraction. The material shows a structural chan...

Magnetic ordering in pressure-induced phases with giant spin-driven ferroelectricity in multiferroic TbMnO 3

In order to clarify the mechanism associated with pressure/magnetic-field-induced giant ferroelectric polarization in

Magnetotransport Studies of EuFe2As2: The Influence of the Eu2+ Magnetic Moments

{\mathrm{TbMnO}}_{3}

Manipulating 4 f quadrupolar pair-interactions in Tb B 2 C 2 using a magnetic field

, this work investigated changes in magnetic ordering brought about by variations in temperature, magnetic field, and pressure. This was accomplished by means of neutron diffraction analyses under high pressures and high magnetic fields, employing a single crystal. The incommensurate magnetic ordering of a cycloid structure was found to be stable below the reported critical pressure of 4.5 GPa. In contrast, a commensurate

Magnetization Process in GdB4

E

Magnetic properties of Ce3Pd20Si6 at very low temperatures

-type spin ordering of Mn spins and a noncollinear configuration of Tb spins with

Manipulating4fquadrupolar pair-interactions inTbB2C2using a magnetic field

\mathbit{k}=(0,\frac{1}{2},0)

Manipulating 4f quadrupolar pair-interactions in TbB2C2 using a magnetic field

appeared above 4.5 GPa. The application of a magnetic field along the