Oscillation in the Interlayer Coupling of Fe Films Across Cr Films Measured by Means of Light Scattering from Spin Waves and M(H)-Curves

1991 ◽  
Vol 231 ◽  
Author(s):  
S. Demokritov ◽  
J.A. Wolf ◽  
P. GrÜnberg ◽  
W. Zinn
Keyword(s):  
Light Scattering ◽  
Temperature Dependence ◽  
Exchange Interaction ◽  
Long Range ◽  
Type Theory ◽  
Short Range ◽  
Spin Waves ◽  
Interlayer Coupling ◽  
Zero Temperature ◽  
Cr Film

AbstractBy means of light scattering from spin waves and magnetooptical Kerr measurements we investigated the exchange interaction of two Fe films across a Cr film as a function of the Cr thickness dCr.Using good quality epitaxial samples with a special wedge geometry of the interspacer we observed up to four full periods of the long range oscillations of the exchange, including its ferromagnetic parts. At room temperatures the damping of the oscillations does not follow the d-2Crpendence predicted by zero-temperature RKKY-type theory.After a special e-beam treatment of the samples a short-range oscillation with a period around a lattice constant of Cr are discovered. The value of coupling in the maximum in this case shows considerable temperature dependence.The analysis of domain patterns and M(H) curves reveals the existence of a noncollinear interaction, which causes a configuration where the magnetizations of two Fe films are perpendicular to each other.

scholarly journals Spin Waves Excitations of Co/Pt Multilayers

2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
W. Zhou
Keyword(s):  
Magnetic Field ◽  
Light Scattering ◽  
External Magnetic Field ◽  
Spin Waves ◽  
Perpendicular Magnetic Anisotropy ◽  
Interlayer Coupling ◽  
Thickness Change ◽  
Single Spin ◽  
Field Situation ◽  
Scattering Measurements

The present work investigated interlayer couplings of [Co(20 Å)/Pt(30 Å)]5, [Co(4 Å)/Pt(7 Å)]30, and [Co(4 Å)/Pt(9 Å)]30multilayers with strong perpendicular magnetic anisotropy (PMA). Brillouin light scattering measurements were utilized to obtain spin waves of these samples with in-plane external magnetic fields. Interlayer couplings were found to be very sensitive to Pt thickness change from 7 Å to 9 Å, which implies that Pt atoms were more difficult to be polarized to provide interlayer coupling between Co layers than in the perpendicular external magnetic field situation. When Pt layer is 30 Å, the observed single spin wave can confirm the disappearance of interlayer coupling even when Co layer thickness is 20 Å.

Magnetic Field Induced Berezinskii-Kosterlitz-Thouless Correlations in 3-Dimensional Manganites

MRS Advances ◽  
2020 ◽  
Vol 5 (44) ◽  
pp. 2251-2260
Author(s):  
A. Ashoka ◽  
Bhagyashree K. S. ◽  
S. V. Bhat
Keyword(s):  
Magnetic Field ◽  
Temperature Dependence ◽  
Long Range ◽  
Interlayer Coupling ◽  
Xy Model ◽  
Paramagnetic Resonance ◽  
3 Dimensional ◽  
Range Magnetic Order ◽  
Antiferromagnetic Transitions ◽  
Long Range Ordering

AbstractIdeal two-dimensional (2D) Heisenberg magnets lack long range magnetic order. However, the XY model with spins confined to a plane shows a topological phase transition at a finite temperature corresponding to binding and unbinding of vortices. Experimental evidence for such Berezinskii-Kosterlitz-Thouless (BKT) transitions has been difficult to obtain in condensed matter systems, where, even a weak interlayer coupling that is invariably present leads to long-range order, pre-empting the BKT transition. The BKT signatures are still discernible above the long-range ordering temperature, however, in the characteristic exponential temperature dependence of the coherence length of the fluctuations. In this work we report that an applied magnetic field can induce such BKT correlations not only in quasi 2-dimensional systems but also in nominally 3-dimensional manganites undergoing antiferromagnetic transitions. We arrive at this unexpected conclusion based on our studies of temperature dependence of electron paramagnetic resonance (EPR) linewidth ΔH(T) of Cr3+ doped bismuth strontium manganite Bi0.5Sr0.5Mn1-xCrxO3 (x= 0.04, 0.1) (BSMCO04 and BSMCO10).

PARALLELIZATION OF SHORT- AND LONG-RANGE CELLULAR AUTOMATA ON SCALAR, VECTOR, SIMD AND MIMD MACHINES

1991 ◽  
Vol 02 (03) ◽  
pp. 755-772 ◽  
Author(s):  
G.A. KOHRING
Keyword(s):  
Cellular Automata ◽  
Long Range ◽  
Short Range ◽  
Fluid Flows ◽  
Programming Approach ◽  
The Sun ◽  
Zero Temperature ◽  
Connection Machine ◽  
Different Levels ◽  
Computer Type

Algorithms exhibiting parallelization on many different levels are discussed for short-and long-range cellular automata implemented on scalar, vector, SIMD and MIMD machines. Short range cellular automata are commonly used for simulating hydrodynamic fluid flows, while long range cellular automata are applicable to neural networks at zero temperature. A common programming approach based upon multi-spin coding and including higher levels of parallelization when possible, has been used to implement these models on the SUN SPARC-1, the IBM-3090, the Alliant FX/2800, the NEC-SX3/11, the Cray-YMP/832 and the Connection Machine, CM-2. Section 4 of the paper compares the performance of these computers for the algorithms discussed in the text. Additionally, the major subroutines for each computer type are given in the Appendix.

Two-electron exchange interaction in the quasimolecular systems with long-range dipole potential

2015 ◽  
Vol 38 (0) ◽  
pp. 45-55
Author(s):  
О. Мирославович Карбованець ◽  
Мирослав Іванович Карбованець ◽  
Володимир Юрійович Лазур ◽  
М. В. Хома
Keyword(s):  
Exchange Interaction ◽  
Long Range ◽  
Electron Exchange ◽  
Dipole Potential ◽  
Electron Exchange Interaction

scholarly journals Structural basis of long-range to short-range synaptic transition in NHEJ

Nature ◽  
2021 ◽  
Author(s):  
Siyu Chen ◽  
Linda Lee ◽  
Tasmin Naila ◽  
Susan Fishbain ◽  
Annie Wang ◽  
...  
Keyword(s):  
Long Range ◽  
Short Range ◽  
Structural Basis

scholarly journals Comparison of short-range order in irradiated dysprosium titanates

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Roman Sherrod ◽  
Eric C. O’Quinn ◽  
Igor M. Gussev ◽  
Cale Overstreet ◽  
Joerg Neuefeind ◽  
...  
Keyword(s):  
Long Range ◽  
Short Range ◽  
Structural Model ◽  
Ion Irradiation ◽  
Function Analysis ◽  
Ion Beam ◽  
Structural Response ◽  
Heavy Ion ◽  
Range Order ◽  
Radiation Resistant

AbstractThe structural response of Dy2TiO5 oxide under swift heavy ion irradiation (2.2 GeV Au ions) was studied over a range of structural length scales utilizing neutron total scattering experiments. Refinement of diffraction data confirms that the long-range orthorhombic structure is susceptible to ion beam-induced amorphization with limited crystalline fraction remaining after irradiation to 8 × 1012 ions/cm2. In contrast, the local atomic arrangement, examined through pair distribution function analysis, shows only subtle changes after irradiation and is still described best by the original orthorhombic structural model. A comparison to Dy2Ti2O7 pyrochlore oxide under the same irradiation conditions reveals a different behavior: while the dysprosium titanate pyrochlore is more radiation resistant over the long-range with smaller degree of amorphization as compared to Dy2TiO5, the former involves more local atomic rearrangements, best described by a pyrochlore-to-weberite-type transformation. These results highlight the importance of short-range and medium-range order analysis for a comprehensive description of radiation behavior.

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