Microwave Measurement of Magnetic Bubble Collapse and Stripout Field

Abstract

The first use of magnetic resonance apparatus for measurement of the bubble collapse field, Hcol, and the bubble stripout field, Hso, is reported. A low field peak with a distinctive line shape is observed at applied fields corresponding to Hcol (increasing field sweep) or Hso (decreasing field sweep). A standard EPR apparatus with a high‐Q cavity was used at 9.52 GHz. Hcol was determined over the temperature range −50°C to 125°C and as a function of the field angle from perpendicular. These data were corroborated by vibrating sample magnetometer measurements. The ease of temperature control and the applicability to bubbles which are difficult to observe optically due to small size are attractive features of the microwave technique.