Synthesis of Antiferromagnetic Macromolecular Particles

Abstract

KMnF3 and NaMnF3 in bulk are antiferromagnets with a TN of 88.3 K and 66 K respectively. Each are easily precipitated by mixing excess NaF or KF and MnC12. This same reaction can be carried out in the water pools of reverse micelles. By using dioctyl sulfosuccinate (AOT) and isooctane, reverse micelles can be made with a water pool of a specific size controlled by the water/surfactant ratio. This combination of oil phase, surfactant, and aqueous solutions allows a unique opportunity for the fabrication for macromolecular sized materials with narrow size distributions. Using the reverse micelle technique, we synthesized 30 nm particles of NaMnF3 and KMnF3. The particles have a narrow size distribution of <10% verified by TEM. Temperature and field dependent magnetic properties will be discussed.