Types of Measurements Using Magnetometers:

We shall now cover the types of measurements possible with the magnetometers to understand the magnetic properties of materials.

(i) Magnetic hysteresis loop measurements:

The magnetic hysteresis loop (M-H) of a magnetic material is not intrinsic one, but depends on various factors including the microstructure of the material. From technological point of view, the tuning of shape of the M-H loop is very important for a particular application. Hence, the measurement of M-H loop stands as a first step in understanding the magnetic properties. Figures 31.02 and 31.03 depict simple and complicated M-H loops of various materials obtained by SQUID and VSM magnetometers.

Figure 31.02: M-H loops of (a) Fe₃O₄ and (b) Fe nanowires [2].

Figure 31.03: M-H loops of Ta(3)/ NiFe (10)/ Cu(1.5)/ NiFe (2)/ IrMn (10)/Ta(3) (nm) characterized in easy and hard axis [3].

This measurement allows to determine various magnetic parameters such as coercivity, saturation magnetization, remanence, anisotropy field for uniaxial anisotropy sample, etc.

Ref.[2]. Han et al, Sci. Rep. 4 (2014) 7493.
Ref.[3]. Hung et al, DOI: 10.5772/52820.