Organization dependent collective magnetic properties of secondary nanostructures with differential spatial ordering and magnetic easy axis orientation

Structure-Correlated Magnetic Resonance Transverse Relaxivity Enhancement in Superparamagnetic Ensembles with Complex Anisotropy Landscape

“…It is seen that the coercivity ( H c ) and remanence ( H r ) have increased by lowering the temperature and shows a maximum at the lowest temperature (5 K). The nature of coercivity and remanence may be attributed to the predominance of Zeeman energy over thermal excitation energy. − The coercivity values are determined to be 37.9, 37.6, and 9.5 Oe for the CEIN, CEAIN, and CSE systems. The CSE system ensures the lowest coercivity.…”

“…The absence of any other significant peaks ensures the absence of any anions. The observed structural property of the developed systems can impact the inherent magnetic behavior, − for which we perform an in-detail collective magnetic behavior.…”

Magnetic memory effect in ensembles of interacting anisotropic magnetic nanoparticles

“…2(a, d) with variation in temperature. The narrow hysteresis nature indicates presence of superparamagnetic state [8] (Table S2, Fig. S15 [22]).…”

“…To reveal the essence of interaction, we analyzed the remanence curves which depend on rotation of irreversible magnetization. It provides evidence related to interaction by use of Henkel plots [8] which is obtained from Direct Current Demagnetization (DCD) as well as Isothermal Remanent Magnetization (IRM) curves (Protocols for IRM/DCD measurement [22]). For single domainnoninteracting system with uniaxial anisotropy, IRM and DCD are correlated using Wohlfarth expression:…”

“…The fluctuation among their magnetic easy axis occurs resulting freezing of super-spins at blocking temperature along their preferred direction [6].When these single domain nanoparticles are congregated, dynamic behavior begins to be utterly dependent on respective strength of interparticle interaction and anisotropy energy [7]. With gradual enhancement in dipolar strength, spin dynamics signalized by effective duration are extended, which can further classify the behavior of nanoparticles [8][9][10][11][12]. The impact of demagnetizing interaction on moment relaxation is explained by Dormann-Bessais-Fiorani (DBF) model [13] and Shtrikman-Wohlfarth model [14] which predict slowing of moment relaxation period with enhancement in dipolar-interaction.…”