Spin Caloritronics in Magnetic Materials

Spin caloritronics investigates the interplay between spin, charge and heat currents in magnetic materials, exploring how thermal gradients can generate and control spin currents without direct electrical injection. Central to this field is the spin Seebeck effect, where a temperature difference across a magnetic layer produces a flow of magnons—collective spin excitations—that can be converted into an electrical signal via the inverse spin Hall effect in an adjacent heavy metal. Complementary phenomena such as the spin Peltier effect, in which spin currents induce localized heating or cooling at magnetic interfaces, offer routes to solid-state thermal management and energy harvesting. Advances in material design, including engineered interfaces and novel magnetic insulators, have enhanced spin-to-heat and heat-to-spin conversion efficiencies. By harnessing magnonic transport and spin–orbit coupling, spin caloritronics aims to develop thermoelectric devices with low thermal resistance, high sensitivity and scalable thin-film architectures, with applications ranging from waste-heat recovery to on-chip cooling and magnetic sensing.

Research from Nature Portfolio

Recent studies have demonstrated that controlled interfacial oxidation in normal-metal/ferromagnet/oxide multilayers can amplify the spin Seebeck effect by an order of magnitude, by reducing exchange coupling at the oxidised region and thus enhancing the temperature difference between magnon and electron populations. Investigations into spin transport in paramagnetic insulators have revealed that efficient propagation of spin currents can occur even in the absence of long-range magnetic order, with spin diffusion lengths comparable to those of high-quality ferrimagnetic garnets. These findings challenge the conventional requirement for strong exchange stiffness and open new avenues for selecting substrates and non-magnetic hosts as spin conduits in caloritronic devices.

Spin Caloritronics in Magnetic Materials publication trend

The graph below shows the total number of articles in spin caloritronics in magnetic materials across all publications each year (not limited to Nature Index journals).

Technical terms

Spin Seebeck effect: Generation of a spin current perpendicular to an applied temperature gradient via magnonic excitations in a magnetic material.

Spin Peltier effect: Localised heating or cooling at a magnetic interface induced by a spin current.

Magnon: Quantum of a spin wave, representing collective oscillations of magnetic moments and acting as carriers of spin angular momentum.

Inverse spin Hall effect: Conversion of a spin current into a transverse electric voltage in a material with strong spin–orbit coupling.

Spin Hall magnetoresistance: Change in electrical resistance of a heavy metal layer caused by spin current reflections at the interface with a magnetic material.

References

1. Enhanced spin Seebeck effect via oxygen manipulation. Nature Communications (2023).
2. Spin transport in insulators without exchange stiffness. Nature Communications (2019).
3. Spin Hall magnetoresistance and spin Seebeck effect in Pt |CoCr2O4 heterostructures. Science and Technology of Advanced Materials (2025).
4. Influence of Thickness and Interface on the Low-Temperature Enhancement of the Spin Seebeck Effect in YIG Films. Physical Review X (2016).
5. Thermal spin transport and energy conversion. Materials Today Physics (2017).