Structural and magnetic properties of M–Ti (M = Ni or Zn) co-substituted M-type barium ferrite by a novel sintering process

Abstract

M 2? (Ni 2? or Zn 2? ) ion together with Ti 4? ion were substituted for two trivalent Fe 3? ions of M-type barium ferrite in the form of Ba(MTi) x Fe 12-2x O 19 (x = 0.30, 0.60, 0.90 and 1.20). Samples were prepared by solid state reaction and sintered by a novel process. The samples were sintered by the sintering process at a high temperature of 1175°C for 6 h and slowly downed to 800°C at a rate of 1°C per 1 min, and then cooled in air. This process could control contract deformation of grains and effectively reduce the pore formation. Under the novel sintering process, with x = 0.30-1.20, co-substitution of M-Ti caused no change to the single phase M-type barium ferrite structure, and the samples exhibited more homogeneous microstructure. The bulk density (q) increased with Zn-Ti contents, and the maximum density was 4.75 g/cm 3 (x = 1.20), which was 89.7 % of theory density (5.29 g/cm 3 ). Magnetic properties such as saturation magnetization (M s ) and coercivity (H c ) decreased with increasing of M-Ti substituted contents. Magnetic permittivity increased first, and then decreased at different x content under Ni-Ti and Zn-Ti substitution.

Growth of large area few-layer or monolayer MoS2 from controllable MoO3 nanowire nuclei

“…As a typical layered TMD, MoS 2 has attracted great interest because of its distinctive electronic, optical, and catalytic properties. [16][17][18][19][20][21] Many methods of obtaining TMD thin lms, especially MoS 2 thin lms, have been investigated, such as the intercalationassisted thermal cleavage method, 22 micromechanical exfoliation, 18 liquid exfoliation, 23 and vapor deposition. 24,25 The traditional micromechanical exfoliation method can produce high quality MoS 2 monolayers, however low yield and uncontrollable layers limit its application in commercially viable devices.…”

Non-layered wurtzite-type extralarge-area flexible ZnO (011̄0) paper-like nanostructures grown by electrostatically induced vapor-phase transport

“…Currently, since the discovery of graphene, 1 the synthesis of two-dimensional (2D) or quasi-2D ultra-thin nanostructures in a variety of material systems is highly desirable. 2 Until now, 2D ultra-thin inorganic graphene-like analogues have been mostly made from hexagonal layered transition-metal dichalcogenide (TMX 2 ) 3 compound semiconductor nanosheets via micromechanical cleavage 4 or a thermal-induced self-intercalated route, [5][6][7] and has been rarely found for other materials. Therefore, methodologically speaking, how to achieve high aspect ratio (width-to-thickness ratio) technologically-important non-layered compound nanosheets remains a large challenge.…”

Amorphous Electrode: From Synthesis to Electrochemical Energy Storage

“…Numerous materials have been designed, developed, and assessed as an electrode for alkali metal ion batteries. [ 81,82 ] Amorphous materials with abundant defects and vacancies reveal remarkable specific capacity (even higher than the theoretical capacity of the corresponding crystal), which helps improve the insertion/extraction of alkali ions (Li + , Na + , and K + ). For example, the classic carbon‐based, Si‐based, and P‐based were reported to be amorphized by a facile ball‐milling method, [ 83 ] revealing improving electrochemical storage performance.…”