Properties of Paramagnetic Materials
Paramagnetic materials show the following properties
It can be said that the materials which acquire a small amount of magnetism towards the magnetic field when they are placed in a magnetic field are called paramagnetic material. It is a form of magnetism whereby certain materials are weakly attracted by an externally applied magnetic field, and form internal, induced magnetic fields in the direction of the applied magnetic field. Atoms, molecules or ions in the paramagnetic materials contain permanent magnetic moments.
Paramagnetic materials have a little, affirmative vulnerability to magnetic fields. They are the substances which are unconvincingly attracted by a magnet. These materials are faintly attracted by a magnetic field and the substance does not preserve the magnetic properties when the outside field is removed. Some examples include; aluminum, chromium, manganese, oxygen, platinum, alkali and alkaline earth metals. Paramagnetic materials include magnesium, molybdenum, lithium, and tantalum.
Paramagnetic materials have the following properties:
(i) Paramagnetic materials, in a magnetic field, tend to move from lower field strength to higher field strength. That means these are attracted feeble by the magnetic field.
(ii) When a paramagnetic material is placed in a magnetic field, the magnetic lines of force slightly tend to pass through the material by bending [Figure].
(iii) Magnetic induction B of a paramagnetic material is slightly larger than the applied magnetic field intensity H.
(iv) The value of permeability of a paramagnetic material is slightly larger than I.
(v) Magnetic susceptibility of a paramagnetic material (K) does not depend on the magnetic field intensity.
(vi) Removing the magnetizing field, the paramagnetic lose their magnetization. the magnetic lines of forces due to the applied field are attracted towards the paramagnetic material.
(vii) It develops feeble magnetization along the way of a magnetic field. When suspended in a uniform magnetic field, paramagnetic materials turn so as to bring their longest axis along the direction of the magnetic field and shorter axis vertical to the field.
(viii) When placed in a non-uniform magnetic field, the paramagnetic materials move from weaker parts of the field to the stronger parts. When suspended generously in a uniform magnetic field, it aligns itself in the way of a magnetic field.
(ix) Permeability of paramagnetic substance is greater than 1. It moves from weaker to stronger parts of the magnetic field.
(x) The magnetic vulnerability of paramagnetic material is affirmative but little. The magnetic lines of force favor to pass through the material. Susceptibility has a low optimistic value. (For example, χm for aluminum is +0.00002).
Paramagnetic substances are those in which each atom or molecule has a net non-zero magnetic instant of its own. When placed in a non-uniform magnetic field, they have a propensity to move from the weaker part to the stronger part of the field. They get magnetized in the way of the field as shown in Fig.
Susceptibility of paramagnetic materials varies inversely as the temperature of the material. That is they lose their magnetic nature with an increase in temperature. When suspended generously in a uniform magnetic field, they set themselves equivalent to the way of the magnetic field. Examples: Al, Pt, Cr, O2, Mn, CuSO4, etc.