The effect of quasi-hydrostatic pressure upon the ferromagnetic ground state of magnetodielectric, double-
perovskite La₂ MnNiO₆ is investigated using x-ray absorption spectroscopy and diffraction measurements in a
diamond anvil cell. The Mn-O-Ni superexchange interaction that gives rise to ferromagnetism in this cation-
ordered structure is stable to at least 38...
Epitaxial LaRh₁/₂Mn₁/₂O₃ thin films have been grown on (001)-oriented LaAlO₃ and SrTiO₃ substrates using pulsed laser deposition. The optimized thin film samples are semiconducting and ferromagnetic with a Curie temperature close to 100 K, a coercive field of 1200 Oe, and a saturation magnetization of 1.7μB per formula unit. The...
We report on the effects of spin fluctuations, magnetic ordering, and external magnetic field on the
dielectric constant of the ferromagnet SeCuO₃, and the antiferromagnet TeCuO₃. A model based on the
coupling between uniform polarization and the q-dependent spin-spin correlation function is presented
to explain the different behaviors for these...
The recent quest for improved functional materials like high permittivity dielectrics and/or
multiferroics has triggered an intense wave of research. Many materials have been checked for their
dielectric permittivity or their polarization state. In this report, we call for caution when samples are
simultaneously displaying an insulating behavior and a...
The growth of YMn₀.₃₅In₀.₆₅O₃ thin films and their optical and magnetic behavior are reported. The YMn₀.₃₅In₀.₆₅O₃ thin film grows along the (0001) orientation with hexagonal structure similar to YMnO₃ on c-plane sapphire. The film shows paramagnetic behavior in the temperature range measured. The film exhibits a blue color due to...
n-Type In-filled CoSb₃ is a known skutterudite compound that has shown promising thermoelectric (TE) properties resulting in high dimensionless figure of merit values at elevated temperatures. Use in various waste heat recovery applications will require survival and operation after exposure to harsh thermal cycling environments. This research focused on uncovering...
Interstitially filled skutterudites are a promising class of state-of-the-art thermoelectric
materials. Although thermoelectrics are exposed to significant thermal stresses, little
information is known about the fracture toughness of interstitially doped skutterudites. This
work explores the fracture toughness of undoped Co₄Sb₁₂ and indium doped In₀.₁Co₄Sb₁₂
skutterudites using three methods: 1) Vickers...
The solid solutions of InGa₁₋ₓFeₓCuO₄, InFeCu₁₋ₓMgₓO₄, and InGa₁₋ₓFeₓCu₁₋ₓMgₓO₄ were
synthesized and characterized through the use of X – ray and neutron diffraction, and DC –
magnetism measurements. All compositions of InGa₁₋ₓFeₓCuO₄ are single phase and crystallize
in the R3m space group, but a transformation to the spinel InFeMgO₄ structure was...
Complete solid solutions with the composition Na₃M₂₋ₓM’ₓSbO₆ where M, M’ = Cu, Mg, Ni, Zn have been synthesized by conventional solid state techniques and were investigated using X-ray diffraction, magnetism and optical measurements. All compositions crystallize in a monoclinic unit cell and exhibit a layered structure with a honeycomb cationic...
Hexagonal AMO₂ and AMO₃ phases have the same basic structure, and intermediate compositions for this structure have been prepared by topotactic oxidation of AMO₂ phases such as RCuO₂, where R is a trivalent rare earth cation. We now find that such intermediate phases can also be prepared by topotactic reduction...