Al/TiO_(2) self-combustion synthesis reaction has been studied,including the effect of initial conditions of reactants on combustion temperature,combustion velocity and combustion stability etc.The reaction mechanism ...Al/TiO_(2) self-combustion synthesis reaction has been studied,including the effect of initial conditions of reactants on combustion temperature,combustion velocity and combustion stability etc.The reaction mechanism of Al/TiO_(2) self-combustion synthesis has been studied emphatically and the dynamic reaction model has been created.展开更多
In the present investigation,a facile synthesis method is explored involving a self-combustion of a solid precursor mixture of iron oxide Fe_(2)O_(3) and boric acid(H_(3)BO_(3))using camphor(C_(10)H_(16)O)as fuel in a...In the present investigation,a facile synthesis method is explored involving a self-combustion of a solid precursor mixture of iron oxide Fe_(2)O_(3) and boric acid(H_(3)BO_(3))using camphor(C_(10)H_(16)O)as fuel in ambient air in order to form a single phase Fe_(3)BO_(6) crystallites.X-ray diffraction(XRD),Field emission electron microscopy(FESEM),magnetic,and dielectric properties of as prepared sample are studied.From XRD pattern,a single phase compound is observed with an orthorhombic crystal structure(Pnma space group),with average crystallite size of 42 nm.A reasonably uniform size distribution of the plates and self-assemblies is retained in the sample.A magnetic transition is observed in dielectric permittivity(at-445 K)and power loss(at-435 K)when plotted against temperature.A weak peak occurs near 330 K due to the charge reordering in the sample.For temperatures above the transition temperature,a sharp increase of the dielectric loss is observed which occurs due to the presence of thermally activated charge carriers.A canted antiferromagnetic Fe_(3)þordering in a Fe_(3)BO_(6) lattice with a localized charge surface layer is an apparent source of exhibiting a ferroelectric feature in this unique example of a centrosymmetric compound.An induced spin current over the Fe sites thus could give rise to a polarization hysteresis loop.Due to the presence of both ferromagnetic as well as polarization ordering,Fe_(3)BO_(6) behaves like a single phase multiferroic ceramics.展开更多
基金Supported by the National Natural Science Foundation of China。
文摘Al/TiO_(2) self-combustion synthesis reaction has been studied,including the effect of initial conditions of reactants on combustion temperature,combustion velocity and combustion stability etc.The reaction mechanism of Al/TiO_(2) self-combustion synthesis has been studied emphatically and the dynamic reaction model has been created.
基金supported by Science and Engineering Research Board,DST,New Delhi,Government of India(Grant no.:PDF/2016/003784).
文摘In the present investigation,a facile synthesis method is explored involving a self-combustion of a solid precursor mixture of iron oxide Fe_(2)O_(3) and boric acid(H_(3)BO_(3))using camphor(C_(10)H_(16)O)as fuel in ambient air in order to form a single phase Fe_(3)BO_(6) crystallites.X-ray diffraction(XRD),Field emission electron microscopy(FESEM),magnetic,and dielectric properties of as prepared sample are studied.From XRD pattern,a single phase compound is observed with an orthorhombic crystal structure(Pnma space group),with average crystallite size of 42 nm.A reasonably uniform size distribution of the plates and self-assemblies is retained in the sample.A magnetic transition is observed in dielectric permittivity(at-445 K)and power loss(at-435 K)when plotted against temperature.A weak peak occurs near 330 K due to the charge reordering in the sample.For temperatures above the transition temperature,a sharp increase of the dielectric loss is observed which occurs due to the presence of thermally activated charge carriers.A canted antiferromagnetic Fe_(3)þordering in a Fe_(3)BO_(6) lattice with a localized charge surface layer is an apparent source of exhibiting a ferroelectric feature in this unique example of a centrosymmetric compound.An induced spin current over the Fe sites thus could give rise to a polarization hysteresis loop.Due to the presence of both ferromagnetic as well as polarization ordering,Fe_(3)BO_(6) behaves like a single phase multiferroic ceramics.