Magnetism and Magnetic Materials

Geomagnetism is the study of the dynamics of the Earth's magnetic field that is produced in the inner core. The main geomagnetic field of the earth is produced by the field of electrically charged particles within the liquid part of the earth's core. The geomagnetic field is used to explore the dynamics of Earth's inside and its surrounding space environment, and geomagnetic data are used.

Earth's magnetic field diverts most of the solar radiation, whose charged particles would otherwise strip away the ozone sphere that protects the Earth from harmful ultraviolet radiation. The study of the past magnetic field of the Earth is known as paleomagnetism. The polarity of the Earth's magnetic field is recorded in igneous rocks, and reversals of the sector area unit as detectable as stripes centered on mid-ocean ridges where the sea floor is spreading, while the stability of the geomagnetic poles between reversals has allowed paleomagnetism to trace the past motion of continents. Reversals also give the base for magneto stratigraphy, a way of dating rocks and sediments.

Nanomaterials are unit chemical substances or materials that are manufactured and used at a very small scale. Nanomaterials can be classified into four types

Nanotechnology is a science, engineering, and technology conducted at the nanoscale, which is about 1 to 100 nanometres. Nano Science and nanotechnology are the study and application of very small things and can be used across all the other scientific fields, like chemistry, biology, physics, materials science, and engineering.

Electromagnetism is a branch of Physics which deals with the magnetic attraction force that occurs between electrically charged particles. Electromagnetic force is one of the 4 fundamental forces and exhibits electromagnetic fields such as light, magnetic & electric fields. This is the basic reason electrons bound to the nucleus and responsible for the complete structure of the nucleus. Electromagnets are broadly used as fundamental elements of other electrical devices like motors, generators, mechanical device solenoids, relays, loudspeakers, hard disks, MRI machines, scientific instruments, and magnetic separation equipment. The other fundamental forces are:

Molecular magnetism is a highly interdisciplinary research field associated with Chemistry, Physics, and Biology. It deals with design, synthesis and physical characterization as well as the theoretical modeling of isolated molecules or gathering of molecules that contain one or more magnetic centers. Molecular magnetism provides an exceptional collection of materials of various magnetic dimensionalities: 0D single-molecule magnets, 1D single-chain magnets, 2D molecular layers and 3D coordination polymers. The types of magnetisms are as follows.

Ferromagnetism and ferrimagnetism happened once the magnetic moments in a magnetic material line up spontaneously at a temperature below the Curie temperature, to produce net magnetization.

Superconductivity could be a set of physical properties determined in certain materials where electrical resistance vanishes and magnetic flux fields are expelled from the material. Any material exhibiting these properties could be a superconductor. It is characterised by the Meissner effect, the whole ejection of magnetic flux lines from the inside of the superconductor during its transitions into the superconducting state. Prominent examples of superconductors include

Such as yttrium barium copper oxide and iron pnictides, the most important application for superconductivity is in producing the large-volume, stable, and high-intensity magnetic fields required for MRI, proton magnetic resonance and NMR.

Materials science and engineering, covers the design and finding of new materials, particularly solids Materials. Materials engineers deals with metals, ceramics, and plastics to make new materials. Scientists deal with the connections between the underlying structure of a material, its properties, its process techniques and its performance in applications. Materials engineers develop, process, and check materials accustomed make a variety of product, from computer chips and aircraft wings to golf clubs and medical devices. Materials Science and Engineering combines engineering, physics and chemistry principles to solve real-world problems associated with nanotechnology, biotechnology, information technology, energy, manufacturing and other major engineering disciplines to handle global challenges relevant to technology, society and the environment, including:

Magnetic method involves the measurement of the earth's magnetic field intensity. Magnetic methods are used to resolve several problems like:

• Mapping the basement surface and sediments in oil/gas exploration


• Detecting various types of ore bodies in mining prospecting


• Detecting metal objects in engineering geophysics

Magnetic surveys record the spatial variation in the Earth's magnetic flux. In marine archaeology, magnetic surveys are often used to detect and map the geology of wreck sites and discover the composition of magnetic materials found on the seafloor. The other types of magnetic fields found in rock include ferromagnetism and remnant magnetism. Ferromagnetism is generated by ferromagnetic materials like the mineral magnetite found in the rocks. Ferromagnetic materials can create their own magnetic field that may not be in line with the Earth's. Magnetic Method Applications:

With the evolution of permanent magnets, such as ferrites, Alnicos, and rare earth magnets, attempts have been made to use these materials in medical applications. These medical applications include their use in dentures, maxillofacial operations, orthopaedics, fracture healing, drug delivery systems, and MRI scanners. Magnetic particles have seek to be valuable tools for manipulation of cells or biomolecules, for transportation of chemical substances or transfer of energy to defined target sites in biological systems, and for clinical diagnostics and therapeutics both in vitro as well as in vivo. Despite the recognition of magnetic bracelets, science has largely disproven the effectiveness of such magnets in treating chronic pain, inflammation, disease, and general health deficiencies. Do not use magnets as a relief for proper medical attention, and avoid them if you have a pacemaker or use an insulin pump.

Magnetic fusion is an approach to produce thermonuclear fusion power that uses magnetic fields to confine fusion fuel in the form of plasma. Fusion reactions combine light atomic nuclei such as hydrogen to form massive ones such as helium, producing energy. Magnetic fusion tries to use the electrical conductivity of the plasma to contain it through interaction with magnetic fields. The magnetic pressure reduces the plasma pressure. The fundamental fusion energy reactions in a laboratory were achieved in 1934 a major breakthrough at the time. There are three states of matter: solid, liquid and gas. If a gas is subjected to very high temperatures, it becomes plasma. In plasma, electrons are rifle from the atoms. An atom with no electrons orbiting around the nucleus is said to be ionized and is called an ion. As a result, plasma is made of ions and free electrons. In this state, scientists can stimulate ions so that they smash into one another, fuse and release energy. Types of Fusion Reactors are:

Magnetic properties are important in several electronic applications like radiation shielding, sensors, and induction heating. Electromagnets are used as key components of transformers in power supplies that convert electrical energy from a wall outlet into direct current energy for a wide range of electronic devices, and in motors and generators. High field superconducting magnets provide the magnetic flux in MRI devices that are now used extensively in hospitals and medical centers.

Spintronic devices those that exploit the spin of electrons rather than their charge rely on effects that produce, control, and detect spin-polarized currents. Spintronic devices comprise magnetic layers that serve as spin polarizers or analysers isolated by non-magnetic layers through which the spin-polarized electrons are transmitted. It provides a new way to manipulate the magnetization of magnetic nano-structures by a spin-polarized current. Spintronic devices produces high speed, high power lasers, lower threshold current, high-density logic, low power, electronic memory devices and optoelectronic devices. Spintronic systems are most often realised in dilute magnetic semiconductors and Heusler alloys and are of particular interest in the field of quantum computing and neuromorphic computing.

Bio-magnetism is the phenomenon of magnetic fields produced by living organisms; it is a subset of bio electromagnetism. In contrast, organism’s use of magnetism in navigation is magnetoception and the study of the magnetic field’s effects on organisms is magneto biology. The fluid dynamics of biological fluids like blood in the presence of static high magnetic fields is investigated. All these magnets are formed by a group of metals called the ferromagnetic metals. These are metals like nickel and iron. Each of these metals has the special property of being able to be magnetized uniformly. Ferro fluid is a liquid that is attracted to the poles of a magnet. This is a colloidal liquid made of nanoscale ferromagnetic or ferrimagnetic, particles suspended in a carrier fluid. Each magnetic particle is closely coated with a surfactant to inhibit clumping.

Magnetic materials include hard magnets and soft magnets. Hard magnet is also known as permanent magnet, which means a large magnetic field is needed to align the magnetic domains. Soft magnetic materials are easily magnetized and demagnetized. The main difference between hard magnetic materials and soft magnetic materials is that hard magnetic materials have high anisotropy field, high coercivity, large hysteresis loop area, and large magnetic field required for technical magnetization to saturation. Due to the low coercivity of the soft magnetic material, it is easy to demagnetize after the technical magnetization reaches saturation and the external magnetic field is removed, while the hard magnetic material due to the high coercivity, after the technical magnetization to saturation and the magnetic field is removed, it will remain long-term very strong magnetism, so hard magnetic materials are also called constant magnetic materials.

Theoretical and computational investigation of magnetic phenomena in bulk alloys, hetero-structures and nanoparticles. The development of theoretical and computational magnetism approaches to the properties of magnetic materials and their applications, which include magnetic recording and an expanding interest in bio-magnetism. Organic materials with extraordinary magnetic properties promise a wide range of light, flexible, and inexpensive alternatives to familiar metal-based magnets. Individual organic molecules with high magnetic moments will be the foundation for design and fabrication of these materials.