Improvement of sputtered Galfenol thin films for sensor applications

• Published in: Smart materials and structures Vol. 19; no. 5; p. 055013
• Main Authors: Adolphi, B, McCord, J, Bertram, M, Oertel, C-G, Merkel, U, Marschner, U, Schäfer, R, Wenzel, C, Fischer, W-J
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01.05.2010; Institute of Physics
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Copper; Deformation; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Galfenol; General equipment and techniques; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Magnetic properties and materials; Magnetomechanical and magnetoelectric effects, magnetostriction; Measurement and testing methods; Physics; Seeds; Sensors; Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing; Silicon; Solid mechanics; Structural and continuum mechanics; Surface layer; Texture; Thin films; Titanium; Buffer layer; Geometrical shape; Bimorph transducer; Magnetostriction; Permeability; Layer thickness; Texture; Galfenol; Thin film devices; Silicon oxides; Morphology; Sputtered coatings; Embedded transducer; Magnetoelastic effects; Nanotechnology; Stress measurement
• ISSN: 0964-1726; 1361-665X
• DOI: 10.1088/0964-1726/19/5/055013

Galfenol Fe83Ga17 films are sputtered on Si wafers without, and with Ti or Ti/Cu metallic seed layers in order to obtain a magnetoelastic layer which is sensitive to bending deformations of the compound structure. The layer thicknesses range from 100 nm to 5 mu m. Layer morphology, texture, and the Villari effect are examined. The texture of the Galfenol films is strongly influenced by the seed layer. No low-index texture components are found for films directly deposited on Si and SiO2. On Ti, a (111) texture is formed on layers with more than 1000 nm thickness. A favorable (110) fiber texture is formed on Ti/Cu. Deforming the bimorphs (Si + layer system) by 0.012%, the Villari effect is detected due to the change in relative permeability. The maximum change occurs for Galfenol films with a thickness of 1 mu m on a Ti/Cu buffer layer. The films open a route to the incorporation of magnetoelastic films into integrated magnetoelastic sensor devices.