Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
吉川 貴史*; 鈴木 基寛*; Ramos, R.*; Aguirre, M. H.*; 岡林 潤*; 内田 健一*; Lucas, I.*; Anadn, A.*; 菊池 大介*; Algarabel, P. A.*; et al.
Journal of Applied Physics, 126(14), p.143903_1 - 143903_11, 2019/10
被引用回数:10 パーセンタイル:45.82(Physics, Applied)Induced Pt ferromagnetism in FeO/Pt/FeO epitaxial trilayer films has been investigated by means of X-ray magnetic circular dichroism (XMCD) at the Pt -edges at various temperatures from 300 K to 12 K, including the metal-insulator transition temperature of FeO ( K). At all the temperatures, we observed clear XMCD signals due to Pt ferromagnetism, the amplitude of which was determined to be 0.39 at 300K and 0.52 at 12 K for the sample with the Pt thickness of nm. Interestingly, these values are comparable to or even greater than those in Pt/3-ferromagnetic-metal (Fe, Ni, Co, and NiFe) junction systems. The results can be interpreted in terms of a possible Fe interdiffusion into the Pt layer and also possible Fe-Pt alloying due to its high-temperature deposition.
Ramos, R.*; 吉川 貴史*; Anadn, A.*; Lucas, I.*; 内田 健一*; Algarabel, P. A.*; Morelln, L.*; Aguirre, M. H.*; 齊藤 英治; Ibarra, M. R.*
AIP Advances (Internet), 7(5), p.055915_1 - 055915_7, 2017/05
被引用回数:20 パーセンタイル:63.69(Nanoscience & Nanotechnology)We report temperature dependent measurements of the spin Seebeck effect (SSE) in multilayers formed by repeated growth of a FeO/Pt bilayer junction. The magnitude of the observed enhancement of the SSE, relative to the SSE in the single bilayer, shows a monotonic increase with decreasing the temperature. This result can be understood by an increase of the characteristic length for spin current transport in the system, in qualitative agreement with the recently observed increase in the magnon diffusion length in FeO at lower temperatures. Our result suggests that the thermoelectric performance of the SSE in multilayer structures can be further improved by careful choice of materials with suitable spin transport properties.
Ramos, R.*; 吉川 貴史*; Aguirre, M.*; Lucas, I.*; Anadn, A.*; 小宅 教文*; 内田 健一*; 安立 裕人; 塩見 淳一郎*; Algarabel, P. A.*; et al.
Physical Review B, 92(22), p.220407_1 - 220407_5, 2015/12
被引用回数:76 パーセンタイル:91.20(Materials Science, Multidisciplinary)Spin Seebeck effects have been investigated in highly crystalline magnetic multilayer films. Voltage as well as power generated by the spin Seebeck effect were found to be significantly enhanced with increasing the number of layers, . This voltage enhancement defies the simple understanding of the spin Seebeck effect and suggests that spin current flowing between the magnetic layers in the thickness direction plays an important role in the multilayer SSE systems and the observed voltage enhancement.
Ramos, R.*; Aguirre, M. H.*; Anadn, A.*; Blasco, J.*; Lucas, I.*; 内田 健一*; Algarabel, P. A.*; Morelln, L.*; 齊藤 英治; Ibarra, M. R.*
Physical Review B, 90(5), p.054422_1 - 054422_6, 2014/08
被引用回数:107 パーセンタイル:94.78(Materials Science, Multidisciplinary)We report a complete characterization of the anomalous Nernst effect (ANE) and its relationship with the anomalous Hall effect (AHE) in FeO. By combining full thermoelectric and electric transport measurements as a function of temperature, we have verified that the universal scaling relation between the anomalous Hall and diagonal conductivities, observed in materials with bad-metal-hopping type of conduction, is also applicable to the thermoelectric transport. We further show that the ANE and AHE are commonly related through the Mott relation, therefore demonstrating its validity for anomalous transport phenomena in materials with conduction in the dirty regime.