S. Landsgesell

Field-Induced Linear Magnetoelastic Coupling in Multiferroic TbMnO3

We have used in-field neutron and x-ray single-crystal diffraction to measure the incommensurability {delta} of the crystal and magnetic structures of multiferroic TbMnO{sub 3}. We show that the flop in the electric polarization at the critical field HC, for field H along the a and b axes, coincides with a first-order transition to a commensurate phase with propagation vector {kappa}=(0,1/4,0). In-field x-ray diffraction measurements show that the quadratic magnetoelastic coupling breaks down with applied field as shown by the observation of the first harmonic lattice reflections above and below HC. This indicates that magnetic field induces a linear magnetoelastic coupling.

Transition from a phase-segregated state to single-phase incommensurate sodium ordering in γ -Na x CoO 2 ( x ≈ 0.53 )

Synchrotron X-ray diffraction investigations of two single crystals of Na_xCoO_2 from different batches with composition x = 0.525-0.530 reveal homogeneous incommensurate sodium ordering with propagation vector (0.53 0.53 0) at room-temperature. The incommensurate (qq0) superstructure exists between 220 K and 430 K. The value of q varies between q = 0.514 and 0.529, showing a broad plateau at the latter value between 260 K and 360 K. On cooling, unusual reversible phase segregation into two volume fractions is observed. Below 220 K, one volume fraction shows the well-known commensurate orthorhombic x = 0.50 superstructure, while a second volume fraction with x = 0.55 exhibits another commensurate superstructure, presumably with a 6a x 6a x c hexagonal supercell. We argue that the commensurate-to-incommensurate transition is an intrinsic feature of samples with Na concentrations x = 0.5 + d with d ~ 0.03.

Magnetic-field-induced transitions in multiferroicTbMnO3probed by resonant and nonresonant x-ray diffraction

Multiferroic

Magnetic-Field-induced Transitions in Multiferroic TbMnO3 Probed by Resonant

{\text{TbMnO}}_{3}

Structure−Property Relationships in the Crystals of the Smallest Amino Acid: An Incoherent Inelastic Neutron Scattering Study of the Glycine Polymorphs

is investigated using x-ray diffraction in high magnetic fields. Measurements on first- and second-harmonic structural reflections due to modulations induced by the Mn and Tb magnetic order are presented as function of temperature and field oriented along the

Structural tuning of magnetism in the orthorhombic perovskite Nd 1 − x Y x MnO 3 : Evidence for magnetic phase separation

a

Development and characterization of a new bio-nanocomposite (bio-NCP) for diagnosis and treatment of breast cancer

and

Polymorphic drugs examined with neutron spectroscopy: Is making more stable forms really that simple?

b

Magnetoelectric properties in orthorhombic Nd1−xYxMnO3: Neutron diffraction experiments

directions of the crystal. The relation to changes in ordering of the rare earth moments in applied field is discussed. Observations below

Antiferromagnetic ordering in a mixed-valent cerium compound CeRuSn

{T}_{N}^{\text{Tb}}