We describe a modified version of a magneto-optical Kerr magnetometer which allows measuring the hysteresis loop of a specific portion of the sample surface. The diameter of the sampled area can be optically tuned from several mm down to 15 μm. High quality hysteresis loops can be measured in a few seconds. Strong fluctuations are observed when the spot diameter is reduced to a few hundred microns or less. These fluctuations are related to the well-known Barkhausen noise here investigated for the first time in a systematic way using optical techniques. Preliminary data for epitaxial Fe grown on MgO are presented. © 2000 American Institute of Physics.
A focused magneto-optical Kerr magnetometer for Barkhausen jump observations
VAVASSORI, Paolo;
2000
Abstract
We describe a modified version of a magneto-optical Kerr magnetometer which allows measuring the hysteresis loop of a specific portion of the sample surface. The diameter of the sampled area can be optically tuned from several mm down to 15 μm. High quality hysteresis loops can be measured in a few seconds. Strong fluctuations are observed when the spot diameter is reduced to a few hundred microns or less. These fluctuations are related to the well-known Barkhausen noise here investigated for the first time in a systematic way using optical techniques. Preliminary data for epitaxial Fe grown on MgO are presented. © 2000 American Institute of Physics.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
