Scanning Thermal Microscopy and Ballistic Phonon Transport in Lateral Spin Valves

• Published in: Physical review letters Vol. 127; no. 3; pp. 1 - 035901
• Main Authors: Stefanou, G., Menges, F., Boehm, B., Moran, K. A., Adams, J., Ali, M., Rosamond, M. C., Gotsmann, B., Allenspach, R., Burnell, G., Hickey, B. J.
• Format: Journal Article
• Language: English
• Published: College Park American Physical Society 16-07-2021
• Subjects: Injectors; Microscopy; Nanotechnology devices; Phonons; Scanning thermal microscopy; Spatial distribution; Spin valves; Substrates; Thermal diffusion
• ISSN: 0031-9007; 1079-7114
• DOI: 10.1103/PhysRevLett.127.035901

Using scanning thermal microscopy, we have mapped the spatial distribution of temperatures in an operating nanoscale device formed from a magnetic injector, an Ag connecting wire, and a magnetic detector. An analytical model explained the thermal diffusion over the measured temperature range (2–300 K) and injector-detector separation (400–3000 nm). The characteristic diffusion lengths of the Peltier and Joule heat differ remarkably below 60 K, a fact that can be explained by the onset of ballistic phonon heat transfer in the substrate.