Sm–Co–Cu–Ti high-temperature permanent magnets

Coercivity of titanium-substituted high-temperature permanent magnets

The temperature dependence of the coercivity of Sm–Co based magnets is investigated by magnetization measurements and model calculations. The Zr-free titanium-substituted Sm–Co material exhibits a positive temperature coefficient of the coercivity (TCC) above room temperature, a reasonable hysteresis-loop shape, and an appreciable coercivity of 12.3 kOe at 500 C for the nominal composition Sm(C...

Sm–Co–Cu–Ti high-temperature permanent magnets

24 segment high field permanent sextupole magnets

We report on the design, construction, and magnetic field measurements of a system of high field sextupole magnets made from NdFeB compounds. The magnets are utilized as a focusing system for neutral hydrogen ~or deuterium! atoms in a polarized atomic beam source based on Stern–Gerlach spin separation. Each magnet consists of 24 segments of permanently magnetized material differing in remanence...

High-temperature series for random-anisotropy magnets.

High-temperature series expansions for thermodynamic functions of random-anisotropy-axis models in the limit of infinite anisotropy are presented, for several choices of the number of spin components, m. In three spatial dimensions there is a divergence of the magnetic susceptibility χM for m=2. We find Tc/J=1.78±0.01 on the simple cubic lattice, and on the face-centered cubic lattice, we find ...

High performance Nd-Fe-B permanent magnets without critical elements

Scanning electron microscopy, and magnetization measurements reveal that as cast (Nd1 xCex)2Fe14B alloys contain significant amounts of a-Fe that can be dramatically reduced by annealing the alloys at 1000 C for 3 days. The room temperature intrinsic coercivity, Hci, of (Nd0.8Ce0.2)2.2Fe14B melt spun ribbons was found to be 11 kOe, which is ~32e~10% higher in comparison to that of Nd2Fe14B (Hci...