Magnetoelectric effect driven by magnetic domain modification in LuFe2O4.

The magnetocapacitance effect was investigated using impedance spectroscopy on single crystals of LuFe(2)O(4). The intrinsic impedance response could be separated from the interfacial response and showed a clear hysteresis loop below T(Ferri)∼240 K under the magnetic field. The neutron diffraction experiment under the magnetic field proves the origin of the dielectric property related to the motion of the nanosized ferromagnetic domain boundary. These results imply that the modification of the microscopic domain structure is responsible for the magnetoelectric effect in LuFe(2)O(4).

Hot Electron Extraction in SWCNT/TiO2 for Photocatalytic H2 Evolution from Water.

Single-walled carbon nanotube (SWCNT)/TiO2 hybrids were synthesized using 1,10-bis(decyloxy)decane-core PAMAM dendrimer as a molecular glue. Upon photoirradiation of a water dispersion of SWCNT/TiO2 hybrids with visible light (λ > 422 nm), the hydrogen evolution reaction proceeded at a rate of 0.95 mmol/h·g in the presence of a sacrificial agent (1-benzyl-1,4-dihydronicotinamide, BNAH). External quantum yields (EQYs) of the hydrogen production reaction photosensitized by (6,5), (7,5), and (8,3) tubes were estimated to be 5.5%, 3.6%, and 2.2%, respectively, using monochromatic lights corresponding to their E22 absorptions (570 nm, 650 nm, and 680 nm). This order of EQYs (i.e., (6,5) > (7,5) > (8,3)SWCNTs) exhibited the dependence on the C2 energy level of SWCNT for EQY and proved the hot electron extraction pathway.

Unicompartmental Knee Arthroplasty for Severe Osteoarthritis and Pseudarthrosis in a Patient with Neurofibromatosis.

We describe the case of a 76-year-old Asian female patient who presented with severe pain and a valgus deformity of the right knee. Her past medical history included neurofibromatosis, which resulted in a severe anterior slope of the right knee, limb shortening, and congenital pseudarthrosis. She was diagnosed with severe anterolateral osteoarthritis and eburnation of the right knee that was treated surgically with a lateral unicompartmental knee arthroplasty (UKA). Bone and cartilage fragments were removed from the joint space and a UKA implant (Zimmer®) with dimensions of 29 mm × 50 mm was inserted. Perioperative imaging revealed that the procedure resulted in the correction of the valgus deformity. Pain was reduced and the patient was able to walk for 10 meters with support during the immediate postoperative period. One week post-surgery, the patient sustained an oblique tibial fracture that extended from the medial edge of the implant to the medial slope of the proximal tibia. This complication may have been attributed to large implant size or sagittal overcutting. The fracture was treated surgically with a rotated anterolateral locking plate (A.L.P.S®) inserted into the distal tibia. The patient was capable of ambulation at full weight load at two months after the second procedure. It is critical to recognize that there are no standard protocols that can be used to guide the treatment of neurofibromatosis-induced osteoarthritis. The specific preoperative condition of the individual patient plays a large role in determining the appropriate treatment option. In this case, the availability of custom-fitted UKA implants might have improved outlook, we understand that these devices are costly and may not be available at all hospitals. However, we strongly believe that the "gold standard" in these cases is patient-specific treatment that addresses the issues of the highest concern using the resources that are available at that time.

Skewed electronic band structure induced by electric polarization in ferroelectric BaTiO3.

Skewed band structures have been empirically described in ferroelectric materials to explain the functioning of recently developed ferroelectric tunneling junction (FTJs). Nonvolatile ferroelectric random access memory (FeRAM) and the artificial neural network device based on the FTJ system are rapidly developing. However, because the actual ferroelectric band structure has not been elucidated, precise designing of devices has to be advanced through appropriate heuristics. Here, we perform angle-resolved hard X-ray photoemission spectroscopy of ferroelectric BaTiO3 thin films for the direct observation of ferroelectric band skewing structure as the depth profiles of atomic orbitals. The depth-resolved electronic band structure consists of three depth regions: a potential slope along the electric polarization in the core, the surface and interface exhibiting slight changes. We also demonstrate that the direction of the energy shift is controlled by the polarization reversal. In the ferroelectric skewed band structure, we found that the difference in energy shifts of the atomic orbitals is correlated with the atomic configuration of the soft phonon mode reflecting the Born effective charges. These findings lead to a better understanding of the origin of electric polarization.

Pure lead nanoparticles with stable metallic surfaces, on perovskite lead strontium titanate particles.

We demonstrate an efficient method of fabrication for pure lead nanoparticles with non-oxidized surfaces, supported on perovskite lead strontium titanate particles with a size distribution from tens to several hundreds of nanometers. The fabrication method is based on co-precipitation and subsequent annealing in air at 600 degrees C. Transmission electron microscopy revealed that the pure lead nanoparticles show structural fluctuations under intense electron-beam irradiation, like gold and platinum nanoparticles.

A gradational system for ferroelectric nanosized (Pb(0.7)Sr(0.3))TiO(3) particles.

Synchrotron radiation x-ray diffraction measurement was performed to investigate the size effect in ferroelectric nanosized (Pb(0.7)Sr(0.3))TiO(3) particles with various sizes ranging from 10 to 200 nm. The 200 and 002 Bragg reflections were separated using low energy synchrotron radiation x-rays. The peak profiles of the 002 reflections show a large broadening and asymmetry for all particle sizes compared with those of the 200 reflections. These anomalously wide and asymmetric peak profiles become marked for peaks with a large l. The aspect ratio of the lattice constants c/a and the atomic distance between the anions and cations decrease gradually in the vicinity of the surface of the particles, indicating that the asymmetrical profiles can be attributed to the formation of a gradational system.

Raman scattering study of Ca-modified lead titanate.

The paraelectric to ferroelectric phase transitions were studied by Raman scattering in Ca-doped lead titanate ceramics. The soft optic modes responsible for the ferroelectric phase transitions were clearly observed. The A(1)(1TO) mode, which softens toward T(c), contains four subpeaks. The frequencies of these subpeaks depend to a great extent on the Ca content and the temperature. These behaviors are discussed on the basis of the anharmonicity of lattice vibrations.

Dynamical properties of the relaxor ferroelectric 0.71Pb(Ni1/3Nb2/3))O3-O.29PbTiO3 probed by Brillouin and Raman scattering.

Abstract-Structural phase transitions in relaxor ferroelectric materials remain to be one of the most puzzling issues in materials science. In the present work, we have investigated relaxational and vibrational properties of a relaxor ferroelectric 0.71Pb(Ni(1/3)Nb(2/3))O(3)-O.29PbTiO(3) single crystal by means of inelastic light scattering measurements. Analysis based on the spectra has shown anomalous behaviors at Burns' temperature T(d), freezing temperature T(f) , those are related to a development of polar nanoregions (PNRs). The PNR must play a key role in the relaxor nature, and obtained results provide new insights into the relaxational dynamics in the PNRs and into how they develop below T(f).

Present status of the experimental aspect of RFe2O4 study.

We give a brief review of the experimental research on a triangular mixed valence iron oxide RFe2O4 (R = Y, Dy, Ho, Er, Tm, Yb, Lu, Sc or In). Interest in this material has been increasing every year because of the fascinating but complicated interaction between spin, charge and the orbital state of iron ions in frustrated geometry. Reports collected in this review cover experimental research on crystallography, chemical analysis, bulk and thin film preparation, magnetic, dielectric, diffraction with neutrons, x-ray and electron, optical and x-ray absorption, Mössbauer spectroscopy and other methods that incorporate the use of modern scientific technology and knowledge. The report mainly focuses on experimental facts since 1990 on which an early review by Siratori has been published (Kimizuka et al 1990 Handbook on the Physics and Chemistry of Rare Earths vol 13, ed K A Gschneidner Jr and L Eyring (Amsterdam: North-Holland/Elsevier) pp 283-384).