Showing papers by "M. R. Ibarra published in 2018"
TL;DR: In this article, the anomalous Nernst effect (ANE) was studied in [Fe3O4/Pt]-based heterostructures, by measuring the ANE-induced electric field with a magnetic field applied normal to the sample surface, in the perpendicular magnetized configuration.
Abstract: We have studied the anomalous Nernst effect (ANE) in [Fe3O4/Pt]-based heterostructures, by measuring the ANE-induced electric field with a magnetic field applied normal to the sample surface, in the perpendicular magnetized configuration, where only the ANE is expected. An ANE voltage is observed for [Fe3O4/Pt]n multilayers, and we further investigated its origin by performing measurements in [Fe3O4/Pt/Fe3O4] trilayers as a function of the Pt thickness. Our results suggest the presence of an interface-induced ANE. Despite of this ANE, the spin Seebeck effect is the dominant mechanism for the transverse thermoelectric voltage in the in-plane magnetized configuration, accounting for about 70 % of the measured voltage in the multilayers.
21 citations
TL;DR: In this paper, the spin Seebeck effect in Ni-Zn ferrites slabs with different Zn concentration was observed and the magnetic properties were characterized by VSM and Mossbauer spectroscopy.
18 citations
TL;DR: In this article, a combination of scanning tunneling spectroscopy and atomic lateral manipulation was used to obtain a systematic variation of the Kondo temperature of Co atoms on Ag(111) as a function of the surface-state contribution to the total density of states at the atom adsorption site.
Abstract: Using a combination of scanning tunneling spectroscopy and atomic lateral manipulation, we obtained a systematic variation of the Kondo temperature ${T}_{\mathrm{K}}$ of Co atoms on Ag(111) as a function of the surface-state contribution to the total density of states at the atom adsorption site ${\ensuremath{\rho}}_{s}$. By sampling the ${T}_{\mathrm{K}}$ of a Co atom on positions where ${\ensuremath{\rho}}_{s}$ was spatially resolved beforehand, we obtain a nearly linear relationship between the magnitudes. We interpret the data on the basis of an Anderson model including orbital and spin degrees of freedom [SU(4)] in good agreement with the experimental findings. The fact that the onset of the surface band is near the Fermi level is crucial to finding the observed linear behavior. In light of this model, the quantitative analysis of the experimental data evidences that at least a quarter of the coupling of Co impurities with extended states takes place through the hybridization to surface states. This result is of fundamental relevance in the understanding of Kondo screening of magnetic impurities on noble-metal surfaces, where bulk and surface electronic states coexist.
17 citations
TL;DR: In this article, the authors presented a work supported by ERATO and PRESTO for Spin Quantum Rectification Project (ERATO-SPRQP), which was performed in the Laboratorio de Microscopias Avanzadas at INA, Universidad de Zaragoza, Spain.
Abstract: This work was supported by ERATO ‘Spin Quantum Rectification Project’ (Grant No. JPMJER1402) and PRESTO ‘Phase Interfaces for Highly Efficient Energy Utilization’ (Grant No. JPMJPR12C1) from JST, Japan; Grantin-Aid for Scientific Research (A) (Grant No. JP15H02012) and Grant-in-Aid for Scientific Research on Innovative Area, ‘Nano Spin Conversion Science’ (Grant No. JP26103005) from JSPS KAKENHI, Japan, the NEC Corporation, and the Noguchi Institute. The microscopy works were conducted in the Laboratorio de Microscopias Avanzadas at INA, Universidad de Zaragoza; H2020-MSCA-RISE-2016 SPICOLOST (Grant No. 734187); the Spanish Ministry of Economy and Competitiveness (Grant No. MAT2017-82970-C2, including FEDER),
Spain; and the Aragon regional government (E26), Spain.
11 citations