scholarly journals Surface and Microstructure Analysis of CoCrPt Film on RuCoCrX (X = Ti, Re) Intermediate Layers

Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 263
Author(s):  
Jai-Lin Tsai ◽  
Jyun-You Chen ◽  
Cheng Dai ◽  
Ting-Wei Hsu ◽  
Shi-Min Weng
Keyword(s):  
Intermediate Layer ◽  
Lattice Misfit ◽  
Anisotropy Constant ◽  
High Coercivity ◽  
Magnetic Anisotropy Constant ◽  
Residual Oxygen ◽  
Intermediate Layers ◽  
Out Of Plane ◽  
Large Asymmetry ◽  
The Ideal

The microstructural and magnetic properties of perpendicular anisotropic CoCrPt films deposited on Ru or RuCoCrX (X = Ti, Re) intermediate layers were studied. The c-axis of CoCrPt grains were promoted by (0002) textured RuCoCr, and RuCoCrX (X = Ti, Re) intermediate layers due to smaller lattice misfit as compared to Ru. The narrower rocking width (Δθ50 = 3.76°) in RuCoCrRe intermediate layer and CoCrPt shows higher out of plane coercivity (Hc = 6.2 kOe), magnetic anisotropy constant (Ku = 6.2 × 106 erg/cm3) and nucleation field (HN = −2.8kOe) as compared to the Ru intermediate layer (Hc = 5.4 kOe, Ku = 5.9 × 106 erg/cm3, HN = −1.6 kOe). The partial intergranular exchange decoupling of CoCrPt grains was observed. The grain boundaries oxides were formed by the residual oxygen in targets and sputtering processes. The minor Cr2O3, CoO, TiO2, ReO3 oxides were investigated by surface analysis. Due to the minor oxides and Cr segregation at grains boundaries, the CoCrPt films present high coercivity. Samples CoCrPt/RuCoCr and CoCrPt/RuCoCrTi present a minimum at 45° but the values are much higher than the ideal Stoner-Wohlfarth theoretical value 0.5 which could be due to fewer natural oxides for magnetic grains separation. In sample CoCrPt/RuCoCrRe, there is an increase of intergranular interaction as indicated by the large asymmetry and the shift of the minimum at lower angles.

scholarly journals Wire Ropes and CFRP Strips to Provide Masonry Walls with Out-Of-Plane Strengthening

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2712
Author(s):  
Elena Ferretti
Keyword(s):  
Steel Wire ◽  
Three Dimensional ◽  
Maximum Load ◽  
Masonry Wall ◽  
Masonry Walls ◽  
Wire Ropes ◽  
Out Of Plane ◽  
Beam Mechanism ◽  
Combined Technique ◽  
The Ideal

The present paper deals with an improvement of the strengthening technique consisting in the combined use of straps—made of stainless steel ribbons—and CFRP (Carbon Fiber Reinforced Polymer) strips, to increase the out-of-plane ultimate load of masonry walls. The straps of both the previous and the new combined technique pass from one face to the opposite face of the masonry wall through some holes made along the thickness, giving rise to a three-dimensional net of loop-shaped straps, closed on themselves. The new technique replaces the stainless steel ribbons with steel wire ropes, which form closed loops around the masonry units and the CFRP strips as in the previous technique. A turnbuckle for each steel wire rope allows the closure of the loops and provides the desired pre-tension to the straps. The mechanical coupling—given by the frictional forces—between the straps and the CFRP strips on the two faces of the masonry wall gives rise to an I-beam behavior that forces the CFRP strips to resist the load as if they were the two flanges of the same I-beam. Even the previous combined technique exploits the ideal I-beam mechanism, but the greater stiffness of the steel wire ropes compared to the stiffness of the steel ribbons makes the constraint between the facing CFRP strips stiffer. This gives the reinforced structural element a greater stiffness and delamination load. In particular, the experimental results show that the maximum load achievable with the second combined technique is much greater than the maximum load provided by the CFRP strips. Even the ultimate displacement turns out to be increased, allowing us to state that the second combined technique improves both strength and ductility. Since the CFRP strips of the combined technique run along the vertical direction of the wall, the ideal I-beam mechanism is particularly useful to counteract the hammering action provided by the floors on the perimeter walls, during an earthquake. Lastly, when the building suffers heavy structural damage due to a strong earthquake, the box-type behavior offered by the three-dimensional net of straps prevents the building from collapsing, acting as a device for safeguarding life.

Microscopic approach to the magnetoelectric coupling in RCrO3

2015 ◽  
Vol 29 (Supplement 1) ◽  
pp. 1550251 ◽  
Author(s):  
A. T. Apostolov ◽  
I. N. Apostolova ◽  
J. M. Wesselinowa
Keyword(s):  
Function Theory ◽  
Weak Ferromagnetism ◽  
Anisotropy Constant ◽  
Magnetoelectric Coupling ◽  
Spin Reorientation ◽  
Microscopic Approach ◽  
Rare Earth Ion ◽  
Multiferroic Properties ◽  
Magnetic Anisotropy Constant ◽  
Moriya Interaction

A microscopic model is proposed to describing the multiferroic properties in [Formula: see text], where [Formula: see text] is the magnetic rare earth ion. Using the Green’s function theory, the weak ferromagnetism and the coercive field are calculated by a balance between the Dzyaloshinskii–Moriya interaction (DMI), the single-ion anisotropy and the exchange interaction. We have discussed the magnetic rotational spin-reorientation (SR) transition between [Formula: see text] and [Formula: see text] phases in [Formula: see text] and the abrupt one between [Formula: see text] and [Formula: see text] in [Formula: see text] calculating the energies in the corresponding phases. The type of the phase transition in [Formula: see text] is determined by the sign of the second magnetic anisotropy constant. In order to investigate the origin of the extraordinary ferroelectricity in [Formula: see text], we have studied the different contributions in the polarization due to the antisymmetric exchange DMI and the magnetostriction arising from the Cr-ordering. It is shown that the polarization is due to the interaction between the magnetic [Formula: see text]- and Cr-ions. The influence of a magnetic field on the polarization and of an electric field on the magnetization are also calculated as an evidence for a strong magnetoelectric coupling in [Formula: see text].

The Effect of Rapid Thermal Treatment on the Structural and Optoelectronic Properties of Epitaxial Gaas on Si Grown With or Without Ge Intermediate Layers

1987 ◽  
Vol 92 ◽  
Author(s):  
El-Hang Lee ◽  
M.Abdul Awal ◽  
E. Y. Chan ◽  
R. L. Opila ◽  
D. C. Jacobson ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Thermal Treatment ◽  
Intermediate Layer ◽  
Optoelectronic Properties ◽  
Gaas On Si ◽  
Intermediate Layers ◽  
Structural And Electrical Properties ◽  
Before And After ◽  
Structural And Optoelectronic Properties ◽  
Raman Characterization

ABSTRACTCharacteristics of MOCVD GaAs grown on Si are compared before and after a rapid thermal treatment. The GaAs-on-Si samples were prepared both with and without a Ge intermediate layer, which is used to accomodate mismatches of lattice, thermal and chemical origin between GaAs and Si. Structural, interfacial, chemical, and electrical changes have been examined. RBS and Raman characterization showed improvement of GaAs crystallinity after RTA. In most cases, the interfaces were found to become sharper after RTA, but chemical interdiffusion was observed to cause some effect on the structural and electrical properties. For gold-contacted GaAs, RTA seems to degrade the electrical and optoelectronic properties via gold interdiffusion into GaAs. Comparative studies of the GaAs/Si and GaAs/Ge/Si samples suggests that the two respond somewhat differently to RTA.

Organization of monkey superior colliculus: intermediate layer cells discharging before eye movements

1976 ◽  
Vol 39 (4) ◽  
pp. 722-744 ◽  
Author(s):  
C. W. Mohler ◽  
R. H. Wurtz
Keyword(s):  
Eye Movements ◽  
Superior Colliculus ◽  
Eye Movement ◽  
Intermediate Layer ◽  
Visual Fields ◽  
Saccadic Eye Movements ◽  
Superficial Layer ◽  
Cell Discharge ◽  
Intermediate Layers ◽  
Dorsal Edge

1. We investigated the characteristics of cells in the intermediate layers of the superior colliculus that increase their rate of discharge before saccadic eye movements. Eye movements were repeatedly elicited by training rhesus monkeys to fixate on a spot of light and to make saccades to other spots of light when the fixation spot was turned off. 2. The eye movement cells showed consistent variations with their depth within the colliculus. The onset of the cell discharge led the eye movement by less time and the duration of the discharge was shorter as the cell was located closer to the dorsal edge of the intermediate layers. The movements fields (that area of the visual field where a saccade into the area is preceded by a burst of cell discharges) of each successive cell also became smaller as the cells were located more dorsally. The profile of peak discharge frequency remained fairly flat throughout the movement field of the cells regardless of depth of the cell within the colliculus. 3. A new type of eye movement-related cell has been found which usually lies at the border between the superficial and intermediate layers. This cell type, the visually triggered movement cell, increased its rate of discharge before saccades made to a visual stimulus but not before spontaneous saccades of equal amplitude made in the light or the dark. A vigorous discharge of these cells before an eye movement was dependent on the presence of a visual target; the cells seemed to combine the visual input of superficial layer cells and the movement-related input of the intermediate layer cells. The size of the movement fields of these cells were about the same size as the visual fields of superficial layer cells just above them...

Temperature Behavior of Magnetization in Multiphase Co-P Powders in Unsaturated Regime

2015 ◽  
Vol 233-234 ◽  
pp. 522-525
Author(s):  
Oksana Anatoljevna Li ◽  
Sergey Viktorovich Komogortsev ◽  
Rauf S. Iskhakov ◽  
Lidia Aleksandrovna Chekanova ◽  
Evgeniy V. Eremin
Keyword(s):  
Magnetic Anisotropy ◽  
Temperature Dependence ◽  
Spontaneous Magnetization ◽  
Anisotropy Constant ◽  
Surprising Result ◽  
Zero Temperature ◽  
Bloch Constant ◽  
Magnetic Anisotropy Constant ◽  
Fitting Parameters ◽  
Good Agreement

In this paper we have proposed a modified expression for the fitting M(T) data in Co-P powders with nanocorundum and nanodiamond precipitates. The expression for M(T) takes into account the effects from both thermal magnetic excitations – Bloch’s T 3/2 law and temperature dependence of the magnetic anisotropy. The fitting parameters are spontaneous magnetization at absolute zero temperature, Bloch constant and order of magnetic anisotropy constant. The obtained Bloch constant is in good agreement with literature data. The order of magnetic anisotropy constant is found to be about 3 that is surprising result and supposedly comes from multiphase nature of the investigated Co-P powder.

Temperature Dependence of Magneto-Mechanical Response in Ni-Mn-Ga Magnetic Shape Memory Alloys

2004 ◽  
Vol 855 ◽  
Author(s):  
Leon M. Cheng ◽  
Garrett Landry ◽  
hannon P. Farrell ◽  
Rosaura Ham-Su ◽  
Calvin V. Hyatt
Keyword(s):  
Magnetic Field ◽  
Mechanical Response ◽  
Anisotropy Constant ◽  
Systematic Investigation ◽  
Critical Magnetic Field ◽  
Effect Of Temperature ◽  
Magnetic Shape Memory ◽  
Magnetic Anisotropy Constant ◽  
Maximum Magnetic Field ◽  
Magnetic Forces

ABSTRACTIn this work, a systematic investigation is being carried out on single crystals of Ni47.8Mn27.5Ga24.7 alloy to determine the effect of temperature on the magneto-mechanical behaviour of the Ni-Mn-Ga alloys. Repeated mechanical and magnetic forces have been applied at various temperatures below the martensite finish (MF) temperature. It has been observed that twinning start and finish stresses, critical magnetic field and maximum magnetic-field-induced strain all remain almost constant within about 20K below MF and then change substantially at lower temperatures. Eventually no magnetic-field-induced strain can be observed at temperatures below 262K. It is proposed that although magnetic anisotropy constant increases with decreasing temperature, it is not sufficient to overcome the increasing twinning stresses required for twin boundary motion at lower temperatures.

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