Evidence For Structural Distortion Research Articles

A novel double perovskite Dy2CoMnO6 as supercapacitor electrode with efficient electrochemical performance

Novel double perovskite oxide Dy2CoMnO6 (DCMO) based electrodes were fabricated for supercapacitor application. Structural studies indicate a monoclinic structure (space group: P21/n). The evidence of structural distortion is observed due to the large extent of decentralization of oxygen electron clouds around Co and Mn atoms in YZ and XZ directions. Micron-sized particles of DCMO constitutes a flat surface of electrodes for faster electrochemical reaction. Room temperature electrochemical performance was investigated using three electrodes set up. Cyclic voltammograms (CV) and Galvanostatic charging–discharging (GCD) curves display significant specific capacitance with super cyclic stability as electrodes. The DCMO electrode shows 87 % cyclic stability over 10,000 cycles. This work produces efficient and stable double perovskite oxide DCMO as electrodes for energy storage applications.

Mechanics of the eukaryotic flagellar axoneme: Evidence for structural distortion during bending.

The sliding doublet mechanism is the established explanation that allows us to understand the process of ciliary and flagellar bending. In this study, we apply the principles of the sliding doublet mechanism to analyze the mechanics of the counterbend phenomenon in sea urchin sperm flagella. When a passive, vanadate-treated, flagellum is forced into a bend with a glass microprobe, the portion of the flagellum distal to the probe exhibits a bend of opposite curvature (counterbend) to the imposed bend. This phenomenon was shown to be caused by the induction of inter-doublet shear and is dependent on the presence of an inter-doublet shear resistance. Here we report that in sea urchin flagella there is systematically less shear induced in the distal flagellum than is predicted by the sliding doublet mechanism, if we follow the assumption that the diameter of the flagellum is uniform. To account for the reduced shear that is observed, the likeliest and most direct interpretation is that the portion of the axoneme that is forced to bend undergoes substantial compression of the axoneme in the bending plane. A compression of 30-50 nm would be sufficient to account for the shear reduction from a bend of 2 radians. A compression of this magnitude would require considerable flexibility in the axoneme structure. This would necessitate that the radial spokes and/or the central pair apparatus are easily compressed by transverse stress. © 2016 Wiley Periodicals, Inc.

Spin-reorientation transition in CeMnAsO.

High-resolution X-ray and neutron powder diffraction are used to reveal details of the spin-reorientation transition in the layered oxide pnictide CeMnAsO. Above 38 K, the localized moments on Mn(2+) are antiferromagnetically ordered in a checkerboard fashion within the antifluorite-type MnAs planes and are oriented perpendicular to the planes. Below 38 K, reorientation of these moments into the planes commences. This is complete by 34 K and is coincident with long-range ordering of the Ce(3+) moments. The Ce(3+) and Mn(2+) moments have an arrangement that is different in detail from that in the isostructural NdMnAsO and PrMnSbO. There is no evidence for structural distortion, as found for PrMnSbO and related Pr(3+)-containing compounds, although there is evidence for a very slight (0.025%) misfit between the magnetic and structural cells below the spin-reorientation transition. It is clarified that neutron powder diffraction methods are unable to distinguish between collinear and noncollinear arrangements of manganese and lanthanide moments when the moments have a component parallel to the MnAs planes. A proposal from computational analysis that NdMnAsO and CeMnAsO should adopt different magnetic structures on the basis of the different balances between biquadratic and antisymmetric exchange interactions should be tested using alternative methods.

EFFECTS OF ALLOYING ON THE MAGNETIC AND STRUCTURAL BEHAVIOUR OF CeFe2

EFFECTS OF ALLOYING ON THE MAGNETIC AND STRUCTURAL BEHAVIOUR OF CeFe₂