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Anisotropic nanocomposite Nd13.5Fe73.3Co6.7Ga0.5B6/a-Fe magnets have been synthesized by compacting Nd–Fe–Co–Ga–B powders with a thin PVD coated a-Fe film followed by hot compaction at 580°C and hot deformation at 760°C with a height reduction of 70%. The magnets have a layered structure, in which alternating layers of the hard and soft phases lay perpendicularly to the pressing direction. Although the thickness of the soft phase is far greater than the size for effective exchange interactions suggested in the current models of exchange coupling, composite magnets demonstrate moderate intrinsic coercivity and good squareness of intrinsic demagnetization curves. [ABSTRACT FROM AUTHOR]

Ultrafine and nanocrystalline states of equiatomic face‐centered cubic (fcc) high‐entropy alloy (HEA) CoCrFeNiMn ("Cantor" alloy) are achieved by high‐pressure torsion (HPT) at 300 K (room temperature, RT) and 77 K (cryo). Although the hardness after RT‐HPT reaches exceptionally high values, those from cryo‐HPT are distinctly lower, at least when the torsional strain lies beyond γ = 25. The values are stable even during long‐time storage at ambient temperature. A similar paradoxal result is reflected by torque data measured in situ during HPT processing. The reasons for this paradox are attributed to the enhanced hydrostatic pressure, cryogenic temperature, and especially large shear strains achieved by the cryo‐HPT. At these conditions, selected area electron diffraction (SAD) patterns indicate that a partial local phase change from fcc to hexagonal close‐packed (hcp) structure occurs, which results in a highly heterogeneous structure. This heterogeneity is accompanied by both an increase in average grain size and especially a strong decrease in average dislocation density, which is estimated to mainly cause the paradox low strength. [ABSTRACT FROM AUTHOR]