Microstructure and magnetic properties of FeAs with coarse-grain and nanocrystalline structure

Thermoelectric, Magnetic Properties and Re-entrant Spin-glass State in MBE Grown FeAs Film on LaAlO3(100) Substrate

“…Similar results have been reported for ball-milled FeAs powders with coarse-grain. 7 Apparently, the bifurcation point is much higher, while the T f is much lower than those reported for fluxgrown FeAs single crystal, 150 and 110 K, respectively. 6 We attribute this phenomenon to the strain of the film and the effects of grains boundary in polycrystalline film, mentioned above.…”

“…3a, the electrical resistivity increases with temperature, indicating a metallic behavior as in bulk FeAs. 7 Initially, the electrical resistivity increases with temperature then undergoes a sharp increase with temperature below 100 K, after that it gradually increases again. The increase in electrical resistivity with temperature is attributed to the increase in electron-phonon scattering.…”

“…It exhibits a metallic behavior in electrical transport. The magnetic phase transition of FeAs is approximate 70 K. [3][4][5][6][7] Selte et al reported the magnetic anisotropy of FeAs with a spin orientation in the ac-plane and the propagation vector along the b-axis, resulting in the collinear antiferromagnetic ordering (collinear spin-density wave) of iron atoms below 77 K. 3 Rodriguez et al reported the non-collinear spin-density wave antiferromagnetism, "helical" magnetic order, at T N ≈ 77 K. 4 Segawa et al reported that helical magnetic order is observed below T N ≈ 70 K and anisotropic antiferromagnetic domains are formed in the helical ordered phase. 5 Zig et al reported the spin-glass magnetic transitions and ferromagnetic-type behaviors over the temperature range of 5-300 K, observed in a self-flux grown single crystal.…”

Controlling Phase in Colloidal Synthesis

“…Metal arsenides are limited in their studies, most of which are related to III–V quantum dots (QDs) or use noncolloidal syntheses such as ball milling . Some colloidal syntheses include work by the Jaramillo group who synthesized orthorhombic CoAs and MoAs crystals and hexagonal Cu 3 As crystals, and the Manna group who did the first colloidal NiAs synthesis .…”

“…Metal arsenides are limited in their studies, most of which are related to III–V quantum dots (QDs) 103 or use noncolloidal syntheses such as ball milling. 104 Some colloidal syntheses include work by the Jaramillo group who synthesized orthorhombic CoAs and MoAs crystals and hexagonal Cu 3 As crystals, 64 and the Manna group who did the first colloidal NiAs synthesis. 105 The Manna group also showed that control of the standard InAs synthesis could be added by mediating the reduction with ZnCl 2 , which improved the size distribution of the product, and allowed for a ZnSe shell.…”