hexagonal axis
Recently Published Documents


TOTAL DOCUMENTS

15
(FIVE YEARS 2)

H-INDEX

6
(FIVE YEARS 0)

2021 ◽  
Author(s):  
Maksym Popov ◽  
Igor Zavislyak ◽  
Hongwei Qu ◽  
A. M. Balbashov ◽  
M. R. Page ◽  
...  

Abstract This report is on the observation and analysis of nonlinear magnetoelectric effects (NLME) for in-plane currents perpendicularly to the hexagonal axis in single crystals and liquid phase epitaxy grown thin films of barium hexaferrite. Measurements involved tuning of ferromagnetic resonance (FMR) at 56-58 GHz in the multidomain and single domain states in the ferrite by applying a current. Data on the shift in the resonance frequency with input electric power was utilized to estimate the variations in the magnetic parameter that showed a linear dependence on the input electric power. The NLME tensor coefficients were determined form the estimated changes in the magnetization and uniaxial anisotropy field. The estimated NLME coefficients for in-plane currents are shown to be much higher than for currents flowing along the hexagonal axis. Although the frequency shift of FMR was higher for the single domain resonance, the multi-domain configuration is preferable for device applications since it eliminates the need for a large bias magnetic field. Thus, multidomain resonance with current in the basal plane is favorable for use in electrically tunable miniature, ferrite microwave signal processing devices requiring low operating power.


2019 ◽  
Vol 85 (9) ◽  
pp. 29-35
Author(s):  
V. V. Krasavin ◽  
A. V. Krasavin

Hexagonal metals (e.g., Be, Zr, Ti) are widely used in the nuclear industry, space and aircraft engineering (in manufacturing of the structural elements operating under extreme conditions). A promising way to improve the quality of products made of them is to improve the physical properties of materials using the natural anisotropy of metal single crystals. The results of studying anisotropy and a comparative analysis of the technical characteristics of the elastic properties of single crystals of hexagonal metals are presented. The equations of the elastic compliance matrix components are derived in the explicit form for arbitrary crystallographic direction proceeding from transformations of the elastic compliance tensor in the principal axes to a new arbitrary coordinate system with a subsequent use of Euler angles. Analytical expressions are presented for the technical characteristics of the elastic properties (shear and Young's moduli, Poisson's ratio) of the single crystals of 10 hep metals for an arbitrary crystallographic direction. The axial symmetry of the characteristics about the hexagonal axis is revealed. The sums of the elastic compliance coefficients which determine the shear moduli and the Poisson's ratios in two mutually perpendicular directions are constant in any crystallographic plane of the single crystal. A comparative analysis of the anisotropy of the elastic properties of single crystals of the studied group of metals revealed auxetic properties of Zn and Be single crystals and the region of crystallographic directions of uniaxia tension, leading to an auxetic effect The auxetic effect in Zn was observed under tension in the directions of the plane perpendicular to the hexagonal axis of the single crystal. The planes of the auxetic effect manifestation in Be single crystals are perpendicular to the directions making an angle of 45° with the hexagonal axis.


2018 ◽  
Vol 185 ◽  
pp. 04023
Author(s):  
Sergey Platonov ◽  
Anatoly Kuchin ◽  
Alexey Volegov ◽  
Alexander Korolev ◽  
Dmitriy Neznakhin ◽  
...  

The magnetization curves of magnetically aligned finely powdered samples of the (TmxPr1-x)2Fe17 compounds have been measured at 4 K. The easy magnetization axis is oriented in the basal plane or along the hexagonal axis for the compounds with x = 0-0.3 and 0.7-1, respectively. This is because of the absence of magnetic ordering in the Tm and Pr subsystems in these ranges, respectively, and because of competing anisotropy of the subsystems. For the compositions with x = 0.4-0.6, both rare-earth subsystems are magnetically ordered and the easy magnetization axis is oriented between the basal plane and the hexagonal axis. The critical fields of FOMPs decrease quickly as the Pr or Tm content decreases in the ranges 0-0.3 and 0.7-1, respectively. The magnetization anisotropy also diminishes as the Tm content becomes smaller than x = 0.7. No influence of the intrinsic microdeformations on the magnetization of the compounds was detected.


2016 ◽  
Vol 50 (7) ◽  
pp. 883-887 ◽  
Author(s):  
P. A. Ivanov ◽  
A. S. Potapov ◽  
T. P. Samsonova ◽  
I. V. Grekhov

MRS Advances ◽  
2016 ◽  
Vol 1 (9) ◽  
pp. 591-596
Author(s):  
Takumi Inoshita ◽  
Yasuhide Inoue ◽  
Yoichi Horibe ◽  
Yasumasa Koyama

ABSTRACTThe multiferroic material YbMnO3 has been reported to exhibit both ferroelectric and antiferromagnetic orders in the ground state. Of these two orders, the ferroelectric order is associated with the P63/mmc-to-P63cm structural transition, which occurs around 1270 K. The interesting feature of the ferroelectric state is that a cloverleaf domain structure with a pseudo-six-fold symmetry is observed in transmission electron microscopy images with the beam incidence parallel to the hexagonal axis. To understand the origin of the formation of the cloverleaf domain structure, we have examined the crystallographic features of the ferroelectric state in YbMnO3 by transmission electron microscopy. In this study, particularly, we adopted the experimental condition that electron beam incidences are perpendicular to the hexagonal axis. It was, as a result, found that there existed various ferroelectric domain structures including the cloverleaf domain structure under the present condition. The notable feature of domain structures found in this study is that each domain structure basically consists of six domains, whose domain boundaries are terminated at one point. Because this feature makes us reminiscent of a discommensurate structure in an incommensurate state, we took high-resolution electron micrographs of areas including domain boundaries. Their analysis indicated that a domain boundary could be identified as a discommensuration with a phase slip of π/3. It is thus understood that the cloverleaf domain structure should be one of domain morphologies for a discommensurate structure, which is related to the break of the translational symmetry.


2013 ◽  
Vol 592-593 ◽  
pp. 67-70
Author(s):  
Vaclav Paidar

Atomic planes at three different positions ABC form the stacking along the <111> directions in the FCC lattice and similarly along the <0001> hexagonal axis in the C40 structure in transition metal silicides. However, the structures of silicides are constituted of several stacking of identical atomic planes at four different positions: AB in C11bstructures of e.g. MoSi2, ABC in C40 structures of e.g. VSi2and ABDC in C54 structures of e.g. TiSi2disilicides. The occurrence of the fourth position essentially influences the properties of defects and consequently the mechanical properties of C40 materials.


1989 ◽  
Vol 22 (2) ◽  
pp. 173-180 ◽  
Author(s):  
S. Hashimoto ◽  
K. Forster ◽  
S. C. Moss

Positional parameters (x, y, z) and anisotropic Debye–Waller factors B ⊥ (normal to the xy plane) and B|| (parallel to the xy plane) have been determined for the Fe and Cl atoms in FeCl3 within the space group R{\bar 3} with a = 6.065, c = 17.42 Å. These are (0, 0, 1/3), B Fe⊥ = 1.75 and B Fe|| = 1.2 Å2 for the Fe atoms at 6(c) positions in the hexagonal-axis representation, and (0.358, 0, 0.078), B Cl⊥ = 1.6 and B Cl|| = 1.55 Å2 for the Cl atoms at 18(f) positions. In addition to the crystallographic parameters, the observed twinning is discussed using the possible variants of ABC and ACB stacking sequences, each of which has two variants with a 60° rotation of the chlorine lattice. One of the four twin variants is found to be strongly enhanced. The fit for these parameters yields a reliability factor R = \sum_{i} \parallel F^{i}_{\rm cal} \mid - \mid F^{i}_{\rm obs}\parallel / \sum_{i} \mid F^{i}_{\rm obs} \mid = 0.60.


1988 ◽  
Vol 41 (6) ◽  
pp. 791 ◽  
Author(s):  
GK White ◽  
RB Roberts

The linear thermal expansion of a natural crystal of willemite (Zn2Si04) has been measured parallel and normal to the hexagonal axis from 2 to 1200 K. The linear coefficient a" is negative below 150 K and al is negative below room temperature. The Grtineisen parameter 'Y is about 0�5 at 1000 K and falls to less than - 1 below 60 K.


Sign in / Sign up

Export Citation Format

Share Document