Magnetic Force Microscopy Study of Zr₂Co₁₁‐Based Nanocrystalline Materials: Effect of Mo Addition

Abstract

The addition of Molybdenum was used to modify the nanostructure and enhance coercivity of rare-earth-free Zr2Co11-based nanocrystalline permanent magnets. The effect of Mo addition on magnetic domain structures of melt spun nanocrystalline Zr16Co84-xMox(x=0, 0.5, 1, 1.5, and 2.0) ribbons has been investigated. It was found that magnetic properties and local domain structures are strongly influenced by Mo doping. The coercivity of the samples increases with the increase in Mo content (x≤1.5). The maximum energy product(BH)maxincreases with increasingxfrom 0.5 MGOe forx=0to a maximum value of 4.2 MGOe forx=1.5. The smallest domain size with a relatively short magnetic correlation length of 128 nm and largest root-mean-square phase shiftΦrmsvalue of 0.66° are observed for thex=1.5. The optimal Mo addition promotes magnetic domain structure refinement and thus leads to a significant increase in coercivity and energy product in this sample.

Magnetic Colloidal Particles in Combinatorial Thin-Film Gradients for Magnetic Resonance Imaging and Hyperthermia

“…The difference in phase angle between free and interacting cantilever oscillation causes a phase shift that increases with increasing bilayers. The larger the phase shift, the better the magnetic properties of the samples [50]. A negative phase shift over small magnetic domains was observed in MFM images.…”

Monodisperse magnetic lecithin-PFP submicron bubbles as dual imaging contrast agents for ultrasound (US) and MRI

“…The hemolysis assay was performed using the method reported in the literature. 9 Briefly, 3 ml of blood was collected in EDTA vials. The blood was centrifuged at 6000 rpm for 10 minutes to separate blood cells from plasma, blood cells (RBCs) were washed 5 times with isotonic PBS.…”

“… 8 Many studies reported the incorporation of hydrophilic iron oxide nanoparticles (IONPs) in the aqueous core of liposomes but only a few research groups showed interest in developing magnetic microbubbles by integrating hydrophobic IONPs in the lipid bilayer for use as negative T2 contrast agent in MRI. 9 …”

“…8 Many studies reported the incorporation of hydrophilic iron oxide nanoparticles (IONPs) in the aqueous core of liposomes but only a few research groups showed interest in developing magnetic microbubbles by integrating hydrophobic IONPs in the lipid bilayer for use as negative T2 contrast agent in MRI. 9 A large body of literature focuses on superior MR contrast enhancement by magnetic microbubbles however, using per-uorocarbons (PFCs) as the core of such liposomes to amplify backscattered signals on ultrasound is still unexplored. Compared to gaseous core, the perurocarbons (PFCs) have poor solubility in both water and blood, are inert, low surface tension and have good compatibility.…”