XXXVIII. On permanent magnetism

Aligned two-phase magnets: Permanent magnetism of the future? (invited)

Permanent Magnetism in Thiol Capped Nanoparticles, Gold and ZnO

In spite of the diamagnetic behavior exhibited by bulk ZnO and Au, a ferromagnetic-like behavior is induced in nanoparticles of both systems by appropriate surface functionalization. By capping with thiol derivatized molecules, magnetic hysteresis is observed even at room temperature, whereas the magnetization has a very little temperature dependence. Capping induces an alteration of their elec...

Xxxviii. Metabolic Studies in Phenylketonuria

F6LLING [1934] discovered that, in certain cases of mental deficiency, phenylpyruvic acid was excreted in the urine. His attention was drawn to the phenomenon by the characteristic colour produced by the addition of ferric chloride solution to the urines of these patients, and he identified the responsible substance as phenylpyruvic acid. Other cases have since been recognized [Penrose, 1935]. ...

Thoughts on galactic magnetism ∗

Magnetic fields in spiral galaxies have strengths of order few 10−6G, and are coherent on scales of several kpc [1]. In several disk galaxies, like M51 and NGC 6946, they are also highly correlated (or anti-correlated) with the optical spiral arms. How do such ordered, large-scale fields arise? One possibility is dynamo amplification of a weak but nonzero seed field ∼ 10−19 − 10−23G, provided t...

Permanent magnetism, magnetic anisotropy, and hysteresis of thiol-capped gold nanoparticles.

We report on the experimental observation of magnetic hysteresis up to room temperature in thiol-capped Au nanoparticles with 1.4 nm size. The coercive field ranges from 860 Oe at 5 K to 250 Oe at 300 K. It is estimated that the Au atoms exhibit a magnetic moment of mu=0.036mu(B). However, Au nanoparticles with similar size but stabilized by means of a surfactant, i.e., weak interaction between...