Larmor precession particles

The determination of the g factor thus requires a measurement of the Larmor and the cyclotron frequency. The electrons cyclotron frequency may conveniently be replaced by w /u> x w, where uj, is the ions cyclotron frequency. This is of advantage because the cyclotron frequency of the ion and the Larmor precession frequency can measured at the same particle. The ratio ujec/ujlc is the charge to mass ratio of the ion to the electron. For the case of Carbon it has been determined in Penning trap experiments by van Dyck and coworkers [16],... 

Larmor precession A precession of the motion of charged particles in a magnetic held. It was first deduced in 1897 by Sir loseph Larmor (1857-1942). Appli to the orbital motion of an electron around the nucleus of an atom in a magnetic held of flux density B, the frequency of precession is given by eB/4Ktnv i, where e and m are the electronic charge and mass respectively, p is the permeability, and vis the velocity of the electron. This is known as the Larmor frequency. 

In an FMR experiment a constant, large, magnetizing field is applied, and a Larmor precession of the particle moments is induced by a small, high-frequency field, perpendicular to H. In the customary FMR technique the spectrometer frequency is fixed (e.g., at 9 and 34 GHz) and the dynamic susceptibility is recorded as a function of the strength and the direction of the external field. 

In a single-domain particle of a-Fe203 the magnetization vector is held in the c-plane perpendicular to the c-axis by the magnetocrystalline field. Mossbauer studies use the 57Fe nucleus as the "observer to record when the relaxation time t becomes shorter than the period for precession of the nuclear spin about the direction of the effective field. Substitution into the equation for the Larmor frequency, or observer relaxation time, with an expression for the frequency factor proportional to the specific volume and anisotropy constant of the oxide gave (26, 27) the relationship ... 

---