Narrow Results

Glasses of the xFe₂O₃·(100-x)[3B₂O₃·KF] system, with 0≤x≤35 mol%, were prepared and investigated by infrared (IR) and Raman spectroscopies in attempt to determine the local structure of glasses. The results shown that BO₃ and BO₄ are the main structural units of the glass system and the iron ions are located in the network as FeO₄ and FeO₆.

Al₂O₃ particles reinforced ZL109 composite was prepared by in situ reaction between Fe₂O₃ and Al. The phases were identified by XRD and the microstructures were observed by SEM and TEM. The Al₂O₃ particles in sub-micron size distribute uniformly in the matrix and Fe displaced from the in situ reaction forms net-like alloy phases with Cu, Ni, Al, Mn ect. The hardness and the tensile strength at room temperature of the composites have a small increase compared with the matrix. However, the tensile strength at 350°C can reach 92.18 MPa, which is 18.87 MPa higher than that of the matrix. The mechanism of the reaction in the Fe₂O₃/Al system was studied by DSC. The reaction between Fe₂O₃ and Al involves two steps. The first step in which Fe₂O₃ reacts with Al to form FeO and Al₂O₃ takes place at the matrix alloy melting temperature. The second step in which FeO reacts with Al to form Fe and Al₂O₃ takes place at a higher temperature.

Glasses belonging to the xFe₂O₃·(100-x)[3B₂O₃·BaO] system, with 0≤x≤50 mol% were prepared and characterized by IR spectroscopy in order to obtain information about the influence of Fe₂O₃ on the local structure in the 3B₂O₃·BaO glass matrix. The mode in which both Fe₂O₃ and BaO influences the structure of glass former B₂O₃ was analyzed.

The temperature dependence of the magnetic susceptibility of xFe₂O₃·(100-x)-[P₂O₅·CaO] glasses with 0<x≤50 mol% have been investigated. These data revealed that the valence states and the distribution of iron ions in the glass matrix depend on the Fe₂O₃ content. For the glasses with x≤1 mol% only Fe³⁺ ions are evidenced. In the case of the glasses with 3≤x≤35 mol% both Fe³⁺ and Fe² ions co-exist in the P₂O₅·CaO glass matrix, the Fe²⁺ ion content is higher than that of the Fe³⁺ ions for glasses with x≥10 mol%. For the glasses with x>35 mol%, the evaluated values of the μ_eff indicate either the presence of Fe⁺ ions or the coordination influence on the magnetic moment of iron ions, but the presence of small quantities of the antiferromagnetic or ferrimagnetic interactions between iron ions in studied temperature range cannot be excluded. The high temperature susceptibility results indicate that the iron ions are isolated or participate in dipole-dipole interactions for glasses with x≤35 mol% and are antiferromagnetically coupled for higher contents of Fe₂O₃.

Glasses from the two systems, xFe₂O₃ · (100-x)[P₂O₅ · CaO] and x(Fe₂O₃ · V₂O₅) · (100-x)[P₂O₅ · CaO] with 0 ≤ x ≤ 50 mol% were prepared under the same conditions and characterized by IR spectroscopy. The way in which Fe₂O₃ and (Fe₂O₃ · V₂O₅) influences the local structure of these glasses was analyzed.

Two vitreous systems, xFe₂O₃·(100-x)[3B₂O₃·MO] (MO⇒KClorCaCl₂) with 0≤x≤5 mol%, were characterized by Raman spectroscopy in attempt to determine the local structure of glasses. The mode of which glass structure is influenced by Fe₂O₃ and CaCl₂-replacement of KCl, is established. The results show that BO₃ and BO₄ are the main structural units of the glass systems.

Glasses of the x(Fe₂O₃·V₂O₅)·(100-x)[P₂O₅·Li₂O] system, with 0≤x≤50 mol%, were prepared and investigated by FTIR spectroscopy in an attempt to determine the local structure of glasses. The interpretation of the obtained IR spectra revealed the presence and the dependence of the local structural units in the studied glasses on the iron and vanadium ions content. The results showed that phosphate units are the main structural units of the glass system and the iron and vanadium ions are located in the network. The increasing of iron and vanadium ions content indicate a gradual decreasing in the number of bridging oxygen ions and an increasing in the number of nonbridging oxygen ions.

A facile and novel bubbling-assisted exfoliating method was developed for the preparation of γ-Fe₂O₃/graphene composite, which showed desirable photocatalytic activity toward methyl orange with excellent cycling abilities and the possible growth mechanism was discussed. Photocatalytic and magnetic properties measurements show that the composite has excellent recyclable degradation efficiency and soft magnetic parameters, which makes the composite magnetically separable in a suspension system and can be recycled without significant loss of catalytic activity.