Scale-invariant magnetic textures in the strongly correlated oxide NdNiO3

AbstractStrongly correlated quantum solids are characterized by an inherently granular electronic fabric, with spatial patterns that can span multiple length scales in proximity to a critical point. Here, we use a resonant magnetic X-ray scattering nanoprobe with sub-100 nm spatial resolution to directly visualize the texture of antiferromagnetic domains in NdNiO3. Surprisingly, our measurements reveal a highly textured magnetic fabric, which we show to be robust and nonvolatile even after thermal erasure across its ordering temperature. The scalefree distribution of antiferromagnetic domains and its non-integral dimensionality point to a hitherto-unobserved magnetic fractal geometry in this system. These scale-invariant textures directly reflect the continuous nature of the magnetic transition and the proximity of this system to a critical point. The present study not only exposes the near-critical behavior in rare earth nickelates but also underscores the potential for X-ray scattering nanoprobes to image the multiscale signatures of criticality near a critical point

New approaches to the study of spinel ferrite nanoparticles for biomedical applications

This chapter is prepared into six different sections. The first part will provide a brief introduction of spinel ferrite nanoparticles synthesis, the use of chelating agents in the sol-gel method, and applications of spinel ferrite nanoparticles in biomedical fields. The second part will cover an overview of the structure and magnetism of spinel ferrites. The third part will present a summary of different types of chelating agents. The fourth part will provide information of the sol-gel synthesis for ceramic nanoparticles. The fifth part will focus on the preparation of cobalt ferrite nanoparticles by sol-gel methods using polyvinyl alcohol (PVA) and citric acid (CA) as chelating agents. The influence of chelating agents on the physical properties and antibacterial property of cobalt ferrite nanoparticles will be highlighted in the last part. A discussion on chelating agent-metal ion formation and the antibacterial mechanisms of spinel ferrite nanoparticles will be presented