A Study of Magnetization in Antiferromagnetic Nanoparticle Systems: Investigating the Effects of Temperature and Magnetic Field on Magnetization in Antiferromagnetic Nanoparticle Systems

Abstract

The purpose of the study is to Magnetization of superparamagnetic system depends ontemperature, external magnetic field and time. It also depends on any history. The study shows zero fieldcooled (ZFC) and field cooled (FC) susceptibilities are plotted as a function of temperature T in the study.First, the system is cooled from room temperature to low temperature without the application of a magneticfield in order to assess ZFC susceptibility. Consequently, magnetic moments of particles are blocked inrandom directions. The next step is to apply a weak magnetic field and then collect data. This measurementrelies heavily on the length of time it takes to collect data. By changing the frequency of the applied acmagnetic field, this observation time can be adjusted in ac magnetization measurements. Dcmagnetization measurements use a time scale of about 100 milliseconds. We obtain a modestmagnetization when the particle's magnetic moments slowly relax in the direction of the applied field. Aparticle's relaxation time depends on its temperature and size. As the temperature rises, the relaxationtime reduces for a particular magnetic nanoparticle system. It is because of this that the magnetizationincreases as the temperature rises. When relaxation time equals observation time, the ZFCmagnetization reaches its peak. For every degree increase in temperature above this limit, a drop in ZFCmagnetization can be observed. FC magnetization is measured by cooling the system from roomtemperature to low temperature in the presence of an external weak magnetic field. Most of the magneticmoments of the particles are aligned with the field direction throughout this procedure. As a result, asubstantial magnetization can be achieved at low temperatures. Increasing the temperature causes thismagnetism to diminish at an almost constant rate. Blocking temperature TB is the temperature where theZFC and FC curves meet, and bifurcation temperature Tbf is where the ZFC and FC curves meet. Thesystem is in a blocked condition below the bifurcation temperature, whereas it stays in asuperparamagnetic state above it.