Fabrication and controlled magnetic properties of Ni/ZnO nanorod heterostructures

Ni metal is evaporated onto the tips of ZnO nanorods, creating magnetic-metal/semiconductor heterostructures (see Figure). Accurate thickness control allows tunable magnetic properties in nanosized magnetic layers on individual nanorods due to a crossover from superparamagnetism to ferromagnetism. These magnetic building blocks have potential as components for nanoscale spin-valve transistors, spin light-emitting diodes, and nonvolatile storage and logic devices.