COMMENTS ON THE SELECTION OF A DISPERSED SAMPLE TO DETERMINE THE MAGNETIC SUSCEPTIBILITY OF THE SAMPLE AND THE DISPERSED PHASE PARTICLES

An analysis has been made of fi eld experimental dependences of the magnetic susceptibility of low-concentration colloids with different values of concentration of the dispersed phase of particles (magnetite). An attempt has been made to generalize them to a single dependence in coordinates in which the ordinate is the concentration-rated susceptibility and thus to determine the magnetic susceptibility of individual particles. It has been shown that the obtained results signifi cantly exceed maximum permissible ones. Furthermore, there is contradiction in them (in using data for one and the same colloid, but with a different concentration of the dispersed phase). This is due to the formation of chains and aggregates of particles. Thus, to determine the magnetic susceptibility of dispersed phase particles, it is necessary to use "hard" dispersed samples, in particular, two-fraction powder samples (with addition of a passive fraction), which ensures the fi xation of the dispersed phase particles. Examples have been given of concentration dependences of the magnetic susceptibility of powder samples (with a dispersed phase of magnetite particles), and also of ferro-impurity particles of sugar sand and farina. These dependences having characteristic linear portions make it possible to obtain data on the magnetic susceptibility of individual ferroparticles
   
Author:  A. V. Sandulyak, A. A. Sandulyak, V. A. Ershova, D. A. Sandulyak, M. N. Polismakova, and D. O. Kiselev
Keywords:  ferroparticles, magnetite, colloid, suspension, powder, low-concentration dispersed phase, magnetic susceptibility
Page:  210