Automation of Squid Based Vibrating Sample Magnetometer using Labview

The operation of the SQUID based vibrating sample magnetometer has been fully automated using LabVIEW.Personal computer is used to interface with a large number of electronic instruments and modules to effectively and comprehensively control the measurement process. The computer controls the stepper motor to locate the sample at the position corresponding to maximum sensitivity and uses a temperature controller to sweep the sample temperature at user desired heating rate by automatically setting parameters to the values which are necessary for optimal temperature control. SQUID output, which is proportional to magnetization of the sample, is phase sensitively detected using a lock in amplifier referenced to the vibration frequency and the measured data is stored in the computer for subsequent analysis. Provision exists for an online display of the plot of magnetization as a function of temperature as the data is acquired. The automation of the SQUID VSM greatly reduces the time required for the magnetization measurement and eliminates the possibility of human errors.