Title :
Rotational hysteresis losses in isotropic media
Author :
Harrison, S.A. ; Street, R. ; Budge, J.R. ; Jones, S.K.
Author_Institution :
Dept. of Phys., Western Australia Univ., Nedlands, WA, Australia
fDate :
9/1/1999 12:00:00 AM
Abstract :
A simple method of measuring magnetic rotational hysteresis losses in isotropic media is described. The method involves measuring the angular deceleration of a sample set rotating in a magnetic field. By using air bearings to minimise friction and allowing the moment of inertia of the rotating system to be varied, a maximum sensitivity of 10 -6 J cycle-1 has been achieved with a precision of 3×10-7 cycle-1. The method has been used to measure rotational hysteresis losses as a function of applied field strength in isotropic samples of γ-Fe2O3, AlNiCo and MQ1, a high coercivity NdFeB permanent magnet alloy. The data from these measurements was found to be in good agreement with that obtained by established methods of measurement
Keywords :
aluminium alloys; boron alloys; cobalt alloys; eddy current losses; iron alloys; iron compounds; magnetic hysteresis; magnetic leakage; magnetic particles; magnetic variables measurement; magnetisation reversal; magnetometers; neodymium alloys; nickel alloys; γ-Fe2O3; AlNiCo; Fe2O3; NdFeB; air bearings; angular acceleration magnetometer; angular deceleration; applied field strength; calibration; high coercivity permanent magnet alloy; induced eddy currents; isotropic media; magnetic reversal mechanisms; magnetic rotational hysteresis losses; maximum sensitivity; measuring method; rotating sample set; varied moment of inertia; Acceleration; Accelerometers; Loss measurement; Magnetic field measurement; Magnetic hysteresis; Magnetic materials; Mechanical variables measurement; Rotation measurement; Shafts; Torque;
Journal_Title :
Magnetics, IEEE Transactions on
