Electron Paramagnetic Resonance spectroscopy
Electron paramagnetic resonance (EPR) spectroscopy, also called electron spin resonance (ESR), is a technique for studying materials with unpaired electrons, such as organic and inorganic radicals, and transition metal complexes. It functions by detecting magnetic properties of electrons. This post covers the science of EPR, its key components, real-world applications, ...
Exchange interaction
Electrons prefer parallel spins due to the quantum mechanical concept of exchange energy, which lowers their system's total energy. This preference is a result of the Pauli exclusion principle and the antisymmetric nature of fermion wavefunctions, reducing Coulomb repulsion and stabilizing the system in quantum mechanical interactions.
The basics of ferromagnetism
Magnetism is the force that is exerted by magnets when they repel or attract each other. It is caused by the motion of electric charges. Electrons can spin like tops, and they orbit
An introduction to Skyrmions
Skyrmions are a class of topological solitons discovered by Tony Skyrme in the 1960s, he used this concept to describe how subatomic particles exist as discrete entities in a nuclear field. The original idea was overshadowed by other theories, however, the same concept is now used to describe a phenomena ...
The Bohr atom model
The Bohr model revolutionized our understanding of the atom. It proposed electrons exist in fixed energy levels, challenging classical physics. This explained the hydrogen spectrum and laid the foundation for quantum mechanics.
Ferromagnetic Resonance (FMR) spectroscopy
Ferromagnetic resonance (FMR) is a powerful tool for investigating magnetism in materials. By applying a microwave field and measuring its absorption, FMR reveals details like a material's magnetization and damping. This excerpt explores the theory behind FMR, including the Kittel formula that describes the resonance condition. We'll also delve into ...
Spin pumping: An Introductory Overview
With STT, we have seen that a current can move magnetization, but the reciprocal effect is also possible, namely the generation of a spin current by magnetization motion. This phenomenon is called spin pumping and it is essential for developing spintronic devices, which utilize the spin of electrons rather than ...
Tunneling effect at semiconductor/oxide interfaces
Electron tunneling is a phenomenon commonly observed at semiconductor/insulator or metal/insulator interfaces, particularly when the insulating layer is thin, typically a few nanometers thick. To grasp its intricacies, let's simplify the scenario.
Giant (GMR) and Tunnel (TMR) magnetoresistance
Giant magnetoresistance (and later Tunnel magnetoresistance) is one of the biggest discoveries in thin-film magnetism. Within 10 years after its discovery, it was already used in commercial devices, such as hard disk drive read heads, changing the world. Just like other magnetoresistive effects, GMR is about the change in resistivity ...
Spin-Transfer Torque: An Introductory Overview
Next to the charge, electrons also posses spins. In normal electronic circuits it is of (hardly) no use, as they are orientated randomly in non-ferromagnetic materials. However, when we integrate ferromagnetic components into these devices, the itinerant electrons can become partially spin polarized, with their spins taking on a more ...
