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| 2. |
- GRANBERG, P, et al.
(författare)
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DYNAMICS OF COUPLED 2-DIMENSIONAL CU(MN) SPIN-GLASS FILMS
- 1991
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Ingår i: Physical Review B Condensed Matter. - 0163-1829 .- 1095-3795. ; 44, s. 4410-4414
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Tidskriftsartikel (refereegranskat)abstract
- Time-dependent susceptibility measurements have been performed on multilayered two-dimensional (2D) 40-angstrom-wide Cu0.865Mn0.135 spin-glass films, separated by Cu interlayers of width 10 < w(il) < 1200 angstrom. It is found that samples with w(il) < 30 angstrom display 3D dynamic behavior. For 30 < w(il) < 600 angstrom a gradual decoupling of the spin-glass layers occurs, and for w(il) greater-than-or-equal-to 600 angstrom typical 2D behavior is observed. The effect of a finite interlayer coupling on the dynamic susceptibility is a distinct crossover from 2D dynamic behavior at short observation times to 3D dynamic behavior at long times. A clear influence on the spin-glass dynamics is still observable for interlayer thicknesses of order 500 angstrom; i.e., multilayered spin-glass films are extremely sensitive probes of the effective range of Ruderman-Kittel-Kasuya-Yosida interaction mediated via metallic interlayers. The results also yield information on the relation between time scale and length scale in relaxation experiments, a fundamental concept of domain theories of the spin-glass phase.
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| 3. |
- KUSHAUER, J, et al.
(författare)
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CROSSOVER FROM LOGARITHMICALLY RELAXING TO PIEZOMAGNETICALLY FROZEN MAGNETIC REMANENCE IN LOW-FIELD-COOLED FE0.47ZN0.53F2
- 1994
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Ingår i: Physical Review B Condensed Matter. - 0163-1829 .- 1095-3795. ; 49, s. 6346-6349
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Tidskriftsartikel (refereegranskat)abstract
- Weak-field-induced magnetization M and temporal relaxation of its remanence mu are investigated in Fe0.47Zn0.53F2 by using Faraday rotation and superconducting quantum interference device (SQUID) magnetometry. Stretched logarithmic decay as predicted by Nattermann and Vilfan is confirmed at T = 2.8 K for freezing fields 3 less-than-or-equal-to B less-than-or-equal-to 4.9 T. At very low fields, 0.001 less-than-or-equal-to B less-than-or-equal-to 1.5 T, virtually constant remanence, mu approximately 44 A/m, is observed. It is due to immobile domains, which form via piezomagnetic coupling to built-in random stress fields.
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| 4. |
- MATTSSON, J, et al.
(författare)
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AGING IN A 2-DIMENSIONAL CUMN SPIN-GLASS
- 1992
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Ingår i: Journal of Magnetism and Magnetic Materials. - 0304-8853 .- 1873-4766. ; 104, s. 1623-1624
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Tidskriftsartikel (refereegranskat)abstract
- Utilizing zero-field cooled magnetization measurements the nonequilibrium dynamics in a 2D spin glass film is investigated. The experiments show that aging is an inherent property of 2D spin glass systems with qualitatively similar features as in 3D systems.
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| 5. |
- MATTSSON, J, et al.
(författare)
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MULTILAYERED SPIN-GLASS FILMS - SENSITIVE PROBES OF RKKY
- 1992
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Ingår i: Journal of Magnetism and Magnetic Materials. - : Elsevier BV. - 0304-8853 .- 1873-4766. ; 104, s. 1619-1620
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Tidskriftsartikel (refereegranskat)abstract
- A new method that uses superstructures of Cu(Mn) spin glass films separated by metallic interlayers to probe the decay with thickness of the RKKY interaction within the interlayers is discussed.
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| 6. |
- Mattsson, J., et al.
(författare)
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Temperature dependence of free energy barriers in a Cu(7 at. % Mn) spin glass
- 1994
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Ingår i: Physica B: Condensed Matter. - : Elsevier BV. - 0921-4526. ; 194-196:1, s. 305-306
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Tidskriftsartikel (refereegranskat)abstract
- Time dependent zero-field-cooled magnetisation measurements have been performed in order to determine the temperature dependence of the free energy barriers, B(T), in the spin glass Cu(7 at% Mn). The results have been analysed using the temperature dependence of the free energy barriers predicted in the droplet model, B( T)∝Δ( T) Lψ where L is the size of the droplet. It is found that as T→0 K, Δ (T)→constant, yielding activated dynamics in agreement with the droplet model. As T→ Tg, Δ (T) decreases but stays finite at Tg. This result is in contrast to the current droplet model where Δ (T)→0 when T→ Tg.
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