The behavior and heat generation effect of a magnetic rod-like particle suspension in an alternating and a rotating magnetic field

Abstract

We have investigated the behavior of magnetic rod-like particles and their relationship with the heat generation effect for both alternating and rotating magnetic fields, by means of Brownian dynamics simulations. As a common feature for both type of magnetic field variations, in the case of significantly strong particle-particle interaction strengths, densely-packed clusters are formed, which do not contribute to the heat generation. For the case of the alternating magnetic field, in the intermediate frequency range, linear thick chain-like clusters are formed and the constituent rod-like particles themselves tend to rotate to follow the change in the field. In contrast, for the case of the rotating field, linear clusters rotate as a whole body to respond to the magnetic field rotation. In both type of magnetic field variations, the magnetic interactions between the constituent particles in a cluster tend to function to suppress the relaxational motion of the rod-like particles, which, as a result, leads to increase in the heat generation effect in certain situations. In a relatively large frequency region, the rotating applied magnetic field gives rise to a larger heat generation effect, whereas in contrast, in the lower frequency region the alternating magnetic field yields the larger heating effect.

Highlights

• The behavior of magnetic rod-like magnetic particles has been elucidated in the case of an alternating and a rotating magnetic field.

• The magnetic interactions between the constituent particles in a cluster tend to suppress the relaxation motion of the rod-like particles.

• The frequency and strength of a time-dependent magnetic field have complex influences on the heating effect.

• In a relatively large frequency region, the rotating applied magnetic field gives rise to a larger heat generation effect.

• In a relatively lower frequency region, the alternating magnetic field is superior to the rotating field.

GRAPHICAL ABSTRACT

KEYWORDS:

• Magnetic rod-like particle
• heat generation effect
• magnetic hyperthermia
• alternating magnetic field
• rotating magnetic field

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

S.S. would like to acknowledge the financial support from Grant-in-Aid for JSPS Fellows (20J22468).