Flexible Magnetic Sensor Based on Fe3O4/Mica Heterostructure

Magnetic sensor can contactlessly monitor current in energy system, whose portability is of great importance in practice. Here we grow the Fe
3
O
4
epitaxial thin film on flexible Mica substrate to realize the flexible magnetic sensor. Based on the anomalous hall effect, we found that the hall bar device shows high sensitivity to magnetic field, even at temperature of over 400K. Especially for the 15 nm-thick film devices with medium growth speed, high sensitivity of~13.6V/(A•T) at range of ±2000 Oe has been achieved, which is comparable to the reported anomalous hall magnetic sensors with large measure range. We further examined the flexibility of the magnetic sensor. Under bending fatigue test, the change of hall resistance is less than 3%, which proves the stability of the device under bending. Our finding reveals that the flexible Fe
3
O
4
/Mica heterostructure can be a good candidate for flexible magnetic sensor that can work at over 400K.