Enhancement in Thermally Generated Spin Voltage at the Interfaces between Pd and NiFe2O4 Films Grown on Lattice-Matched Substrates

Efficient spin injection from epitaxial ferrimagnetic Ni Fe 2 O 4 thin films into a Pd layer is demonstrated via spin Seebeck effect measurements in the longitudinal geometry. The Ni Fe 2 O 4 films (60 nm to 1 μ ) are grown by pulsed-laser deposition on isostructural spinel Mg Al 2 O 4 , Mg Ga 2 O 4...

Descripción completa

Detalles Bibliográficos
Autores: Rastogi, A., Li, Z., Singh, A.V., Regmi, S., Peters, T., Bougiatioti, P., Carsten né Meier, D., Mohammadi, J.B., Khodadadi, B., Mewes, T., Mishra, Rohan, Gázquez, Jaume, Borisevich, A.Y., Galazka, Z., Uecker, R., Reiss, G., Kuschel, T., Gupta, A.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2020
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/232461
Acceso en línea:http://hdl.handle.net/10261/232461
Access Level:acceso abierto
Palabra clave:Spin Seebeck effect
Spin injection
Spintronics
Surface & interfacial phenomena
Ferrimagnets
Ferrites
Magnetic multilayers
Spinel
Descripción
Sumario:Efficient spin injection from epitaxial ferrimagnetic Ni Fe 2 O 4 thin films into a Pd layer is demonstrated via spin Seebeck effect measurements in the longitudinal geometry. The Ni Fe 2 O 4 films (60 nm to 1 μ ) are grown by pulsed-laser deposition on isostructural spinel Mg Al 2 O 4 , Mg Ga 2 O 4 , and Co Ga 2 O 4 substrates with lattice mismatch varying between 3.2 and 0.2%. For the thinner films ( ≤ 330 nm), an increase in the spin Seebeck voltage is observed with decreasing lattice mismatch, which correlates well with a decrease in the Gilbert damping parameter as determined from ferromagnetic resonance measurements. High-resolution transmission electron microscopy studies indicate substantial decrease of antiphase boundary and interface defects that cause strain relaxation, i.e., misfit dislocations, in the films with decreasing lattice mismatch. This highlights the importance of reducing structural defects in spinel ferrites for efficient spin injection. It is further shown that angle-dependent spin Seebeck effect measurements provide a qualitative method to probe for in-plane magnetic anisotropies present in the films.

Similares en LA Referencia