  We demonstrated a flexible thermoelectric (TE) sheet based on the
longitudinal spin Seebeck effect (LSSE) that is especially suitable for
heat-flow sensing applications. This TE sheet contained a Ni0.2Zn0.3Fe2.5O4
film which was formed on a flexible plastic sheet using a spray-coating method
known as ferrite plating. The experimental results suggest that the
ferrite-plated film, which has a columnar crystal structure aligned
perpendicular to the film plane, functions as a unique one-dimensional
spin-current conductor suitable for bendable LSSE-based sensors.
