Types of Measurements Using Magnetometers:

• Based on the values of magnetic parameters such as coercivity and permeability, the ferromagnetic materials are classified into soft and hard magnetic materials.

• While soft magnetic materials find applications in transformers, magnetic flux enhancement, sensor, etc., the hard magnetic materials are mainly used in permanent magnet and storage applications. Schematic of hard and soft M-H loop and few examples are shown in Figure 31.04.

Figure 31.04: (left) Schematic of M-H loop for hard and soft magnetic materials, (middle) M-H loops of (a) the 80 nm Permalloy thin films and (b) the Cu/Permalloy (80 nm) bilayer thin film [4], (right) M-H loop of 5 nm thick FePt film grown on MgO substrate and measured at 4.5 K [5].

Ref.[4]. Li et al, J. Magn. Magn. Mater. 377 (2015) 142.
Ref.[5]. Shima et al, Appl. Phys. Lett. 85 (2004) 2571.