Magnetic bubble detection employing a Hall element larger than a bubble

Experimental results of efficient magnetic bubble detection with a semiconductor Hall element larger than a magnetic bubble by the full use of the magnetic flux from a bubble are described. Experimental results with InSb Hall elements of various geometries for a bubble in YFeO3revealed that the maximum output appeared with a Hall element slightly larger than a bubble. About 4.4 mV with an S/N of 18 dB was obtained at 23 mA with a n-type InSb Hall element of 235 × 105 × 3.5 µm³and 30 Ω for a 98-µm bubble in a 60-µm thick YFeO3at a bias field of 30 G and at a rotating field of 2 Hz. This arrangement may especially be useful for the detection of a small bubble in garnet, because the Hall element can be made larger, resulting in the easier fabrication and higher output.