Why is the giant magnetoresistance proportional to the magnetisation for granular CuCo?

Musa, S.O.; Howson, M. A.; Hickey, B. J.; Wiser, Nathan

doi:10.1016/0304-8853(95)00248-0

Cited by 8 publications

(3 citation statements)

References 5 publications

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“…The GMR is therefore often presumed to be a mathematical function of the overall magnetization M. In the case of purely superparamagnetic ͑SPM͒ behavior, it is supposed to be proportional to M squared. 2,3,6,7 If the behavior is not solely SPM, but the larger particles are ''blocked,'' the model by Wiser 5 and Musa et al 8 provides a functional relationship between the GMR and M that includes terms both linear and quadratic in M. Actually, it is based on the presence of a particle-size distribution with, at any given temperature, the smaller particles being SPM and the larger being blocked. The relative fractions of SPM and blocked particles are temperature dependent.…”

Section: Introductionmentioning

confidence: 99%

Microstructure and properties of giant magnetoresistive granular Au80Co20 alloys

Vrenken

Kooi

Hosson

2001

Journal of Applied Physics

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The relationship between microstructure and giant magnetoresistance (GMR) of granular Au80Co20 was investigated. Two different processing routes were explored. With the melt spinning technique the microstructure appeared to be so coarse that it was not expected to exhibit any substantial GMR effect. On the other hand, with the procedure of solid-solution annealing and water quenching afterwards, a suitable nanostructure was prepared that showed a GMR of 29% at 10 K and 50 kOe. Subsequent annealing causes coarsening of Co particles. In additional spinodal decomposition occurred for a certain temperature range and a loss of coherency of the Co particles with respect to the Au was observed with high-resolution transmission energy microscopy. At magnetic fields above ∼20 kOe, all annealed alloys showed a saturating magnetization, whereas the resistance is still steadily decreasing, challenging the presumed mathematical relationship between GMR and overall magnetization.

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Section: Introductionmentioning

confidence: 99%

Microstructure and properties of giant magnetoresistive granular Au80Co20 alloys

Vrenken

Kooi

Hosson

2001

Journal of Applied Physics

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“…O aspecto da curva obtida mostrado na Figura 64 é típico de curvas de magnetoresistência gigante (GMR) de sólidos granulares, onde a magnetoresistência tem valor negativo e é igual nas três geometrias de medida: p;;, magnetoresistência longitudinal; py, magnetoresistência transversal; e P.L. magnetoresistência perpendicular [2, [74][75][76][77][78][79].…”

Section: Magneto-transporteunclassified

“…Sabe-se que a magnetoresistência gigante depende da estrutura de fases, da conectividade das partículas ferromagnéticas, do tamanho dos domínios magnéticos, do tamanho de partícula da fase não magnética e do alinhamento magnético dos spins eletrônicos, o que a torna diretamente proporcional à magnetização de saturação efetiva da amostra [74][75][76][77][78][79]. Logo, as anomalias encontradas são fortes indícios de que a magnetoresistência na amostra pode estar sendo produzida por dois processos distintos: um devido às partículas com características de multidomínio e outro devido a partículas com características de monodomínio.…”

Section: Magneto-transporteunclassified

Sintese e caracterização do solido granular magnetico Fe-Al2O3

Santos¹

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Fluxograma do processamento sol-gel aplicado na obtenção do sólido granular 26 Fe-Ah03. 2 Principais diferenças de processamento entre as três séries de amostras de 27 Fe-Alz03. Visualização gráfica das condições de redução dos óxidos de F e para Fe metálico 27 aplicadas nas três séries de amostras Fe-Ah03. Di:fratogramas das amostras secas da Série B: (a) BA; (b) BB; (c) BC; (d) BD; e 34 (e) BE. SA = (NH4)zS04 e M = rnagnetita. Di:fratogramas das amostras secas da Série C: (a) CA; (b) CB; (c) CC; (d) CD; e (e) CE. N4==(NH4)4(N03)zS04, N5=(NH4)5(N03)3S04, N A = 0 3 , SA=(NH4)2S04 e FN=NIIJ'e(S04)z. 35 Espectros Mõssbauer a 300 K do material seco da Série A com frações volumétri-37 cas crescentes de Fe total, amostras: (a) AA; (b) AB; e (c) AC. Espectros Mõssbauer a 300 K do material seco da Série B com frações volumétri-38 cas crescentes de Fe total, amostras: (a) BA; (b) BB; (c) BC; (d) BD; e (e) BE. Espectros Mõssbauer a 300 K do material seco da Série C com frações volumétri-39 cas crescentes de Fe total, amostras: (a) CA; (b) CB; (c) CC; (d) CD; e (e) CE Espectros Mõssbauer a 300 K do material seco da Série C, amostra CD, com fra-43 ção volumétrica de Fe total de 51,3 %:(a) a 300 K e (b) a 20 K 10 Di:fratogramas das amostras calcinadas da Série B: (a) BAC; (b) BBC; (c) BCC; 45 (d) BDC; e (e) BEC. F= a-Fez03 e AI= a-Ah03. 11 Di:fratogramas das amostras calcinadas a 300 °C da Série C: (a) CA3; (b) CB3; (c) 48 CC3; (d) CD3; e (e) CE3. TS = N1:4AI(S04)z12Hz0, NF = NIIJ'e(S04)2, F= a-Fe203, MG = y-Fe203 e CH = Fe1403(S04)Is63H20. 12 Difratogramas das amostras calcinadas a 600 °C da Série C: (a) CA6; (b) CB6; (c) 49 CC6; (d) CD6; e (e) CE6. AG = Al2(S04)317H20 e F= a-Fez03.

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Giant magnetoresistance and magnetic properties of (Co0.7Fe0.3)20Cu80 prepared by mechanical alloying

Nagamine

Chamberod

Auric

et al. 1997

Journal of Magnetism and Magnetic Materials

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Why is the giant magnetoresistance proportional to the magnetisation for granular CuCo?

Cited by 8 publications

References 5 publications

Microstructure and properties of giant magnetoresistive granular Au80Co20 alloys

Microstructure and properties of giant magnetoresistive granular Au80Co20 alloys

Sintese e caracterização do solido granular magnetico Fe-Al2O3

Giant magnetoresistance and magnetic properties of (Co0.7Fe0.3)20Cu80 prepared by mechanical alloying

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