Effect of inclined magnetic field on pinning parameters in YBaCuO thin films with columnar defects

2005 ◽  
Vol 426-431 ◽  
pp. 83-87
Author(s):  
T. Sueyoshi ◽  
S. Inada ◽  
T. Fujiyoshi ◽  
K. Miyahara ◽  
T. Ikegami ◽  
...  
2000 ◽  
Vol 14 (25n27) ◽  
pp. 2822-2827 ◽  
Author(s):  
E. Silva ◽  
G. Ghigo ◽  
L. Gozzelino ◽  
C. Camerlingo ◽  
S. Sarti

We present measurements of the magnetic field dependent microwave dissipation in a heavy-ion irradiated thin YBa 2 Cu 3 O 7-δ film, in order to study the effects of columnar defects on the pinning of vortices. Columnar defects were produced at 45° with respect to the c axis. Measurements of the microwave dissipation at 48 GHz were taken as a function of the angle between the field and the c axis, in order to compare the response along and perpendicular to the columns. The field was in the 0.3 T range. Several temperatures near the liquid nitrogen temperature were investigated. We find a dip in the dissipation when the field is aligned to the tracks. The dip is absent when the field is aligned perpendicular to the tracks, and with the same angle with respect to the crystallographic directions. The dip is not very sharp, and shows up for angles as far as 30° from the track directions. From the measurements, we estimate the pinning frequency along the columns at 80 K to be νpc ≃ 25 GHz .


2002 ◽  
Vol 7 (2) ◽  
pp. 45-52
Author(s):  
L. Jakučionis ◽  
V. Kleiza

Electrical properties of conductive thin films, that are produced by vacuum evaporation on the dielectric substrates, and which properties depend on their thickness, usually are anisotropic i.e. they have uniaxial anisotropy. If the condensate grow on dielectric substrates on which plane electrical field E is created the transverse voltage U⊥ appears on the boundary of the film in the direction perpendicular to E. Transverse voltage U⊥ depends on the angle γ between the applied magnetic field H and axis of light magnetisation. When electric field E is applied to continuous or grid layers, U⊥ and resistance R of layers are changed by changing γ. It means that value of U⊥ is the measure of anisotropy magnitude. Increasing voltage U0 , which is created by E, U⊥ increases to certain magnitude and later decreases. The anisotropy of continuous thin layers is excited by inequality of conductivity tensor components σ0 ≠ σ⊥. The reason of anisotropy is explained by the model which shows that properties of grain boundaries are defined by unequal probability of transient of charge carrier.


2021 ◽  
Vol 13 (9) ◽  
pp. 5086
Author(s):  
Fatih Selimefendigil ◽  
Hakan F. Oztop ◽  
Ali J. Chamkha

Single and double impinging jets heat transfer of non-Newtonian power law nanofluid on a partly curved surface under the inclined magnetic field effects is analyzed with finite element method. The numerical work is performed for various values of Reynolds number (Re, between 100 and 300), Hartmann number (Ha, between 0 and 10), magnetic field inclination (γ, between 0 and 90), curved wall aspect ratio (AR, between 01. and 1.2), power law index (n, between 0.8 and 1.2), nanoparticle volume fraction (ϕ, between 0 and 0.04) and particle size in nm (dp, between 20 and 80). The amount of rise in average Nusselt (Nu) number with Re number depends upon the power law index while the discrepancy between the Newtonian fluid case becomes higher with higher values of power law indices. As compared to case with n = 1, discrepancy in the average Nu number are obtained as −38% and 71.5% for cases with n = 0.8 and n = 1.2. The magnetic field strength and inclination can be used to control the size and number or vortices. As magnetic field is imposed at the higher strength, the average Nu reduces by about 26.6% and 7.5% for single and double jets with n greater than 1 while it increases by about 4.78% and 12.58% with n less than 1. The inclination of magnetic field also plays an important role on the amount of enhancement in the average Nu number for different n values. The aspect ratio of the curved wall affects the flow field slightly while the average Nu variation becomes 5%. Average Nu number increases with higher solid particle volume fraction and with smaller particle size. At the highest particle size, it is increased by about 14%. There is 7% variation in the average Nu number when cases with lowest and highest particle size are compared. Finally, convective heat transfer performance modeling with four inputs and one output is successfully obtained by using Adaptive Neuro-Fuzzy Interface System (ANFIS) which provides fast and accurate prediction results.


Heat Transfer ◽  
2021 ◽  
Author(s):  
Hafiz Abdul Wahab ◽  
Syed Zahir Hussain Shah ◽  
Assad Ayub ◽  
Zulqurnain Sabir ◽  
Muhammad Bilal ◽  
...  

2021 ◽  
Vol 31 (5) ◽  
pp. 1-5
Author(s):  
Tetsuro Sueyoshi ◽  
Ryusei Enokihata ◽  
Hiroshi Yamaguchi ◽  
Takanori Fujiyoshi ◽  
Yasuki Okuno ◽  
...  

2021 ◽  
Author(s):  
M. Deivanayaki ◽  
M. Jannath Begam ◽  
A. Henna Shenofer ◽  
B. Arun

2021 ◽  
Vol 7 (3) ◽  
pp. 38
Author(s):  
Roshni Yadav ◽  
Chun-Hsien Wu ◽  
I-Fen Huang ◽  
Xu Li ◽  
Te-Ho Wu ◽  
...  

In this study, [Co/Ni]2/PtMn thin films with different PtMn thicknesses (2.7 to 32.4 nm) were prepared on Si/SiO2 substrates. The post-deposition perpendicular magnetic field annealing (MFA) processes were carried out to modify the structures and magnetic properties. The MFA process also induced strong interlayer diffusion, rendering a less sharp interface between Co and Ni and PtMn layers. The transmission electron microscopy (TEM) lattice image analysis has shown that the films consisted of face-centered tetragonal (fct) PtMn (ordered by MFA), body-centered cubic (bcc) NiMn (due to intermixing), in addition to face-centered cubic (fcc) Co, Ni, and PtMn phases. The peak shift (2-theta from 39.9° to 40.3°) in X-ray diffraction spectra also confirmed the structural transition from fcc PtMn to fct PtMn after MFA, in agreement with those obtained by lattice images in TEM. The interdiffusion induced by MFA was also evidenced by the depth profile of X-ray photoelectron spectroscopy (XPS). Further, the magnetic properties measured by vibrating sample magnetometry (VSM) have shown an increased coercivity in MFA-treated samples. This is attributed to the presence of ordered fct PtMn, and NiMn phases exchange coupled to the ferromagnetic [Co/Ni]2 layers. The vertical shift (Mshift = −0.03 memu) of the hysteresis loops is ascribed to the pinned spins resulting from perpendicular MFA processes.


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