New shock-wave (Hugoniot) and release-adiabatic data for Feo.940 and CaO, to 230 and 175 GPa (2.3 and 1.75 Mbar) respectively, show that both oxides transform from their initial B1 (NaC1-type) structures at about 70 (* 10) GPa. CaO transforms to the B2 (CsC1-type) structure and FeO is inferred to do the same. Alternatively, FeO may undergo an electronic transition, but it probably does not disp...

It has been discovered that magnetite ( Fe304 ) is rapidly oxidized to hematite (o<-Fe 0 ), upon illumination ( X<.310p1 ) in an 02-bear~ni atmosphere. A laboratory investigation has been carried out to determine the kinetics and mechanism of this rapid oxidation process. It has been found that the process consists of a series of constituent reactions which are common to most oxidation mechanis...

in this research, the magnetite nanoparticles (fe304) were prepared by coprecipitation of fe- andginger is a well known spice and flavoring agent which has also been used in traditional medicine inmany countries. ginger contains essential oils including gingerol and zingiberene. it also containspungent principles such as zingerone, and shogaol. in the paper six theoretical methods were used toc...

2014 A review is presented of several magnetic structure studies performed recently by neutron diffraction methods. These include a study of the low temperature transition in Fe3O4 by Hamilton and experiments by Roth on the magnetic structure ambiguities of the transition element monoxides. Recent studies using polarized neutron beam techniques are described and data presented on the ferromagne...

The reduction of bulk mixed oxides of zinc and titanium of various compositions and Zn-Ti-0 crystalline phases was studied in a thermogravimetric apparatus in Hz-H,O-N, gas mixtures at 550-1050°C. Comparative reduction experiments with ZnO were also performed. In the absence of water vapor, activation energies of 24 and 37 kcal mol’ were obtained for ZnO and Zn-Ti-0. resnectivelv. The addition ...

Experimental determinations of the atomic structure of insulating oxide surfaces and metal/oxide interfaces are scarce, because surface science techniques are often limited by the insulating character of the substrate. Grazing incidence X-ray scattering (GIXS), which is not subject to charge effects, can provide very precise information on the atomic structure of oxide surfaces: roughness, rela...

Thin-films of magnetite, F@04 have been produced by the XeCl excimer laser ablation of both Fe304 and metallic Fe targets. The ablation of metallic Fe has been shown to produce about two orders of magnitude smaller concentration of boulders than the ablation of bulk magnetite. The use of single-crystal, latticematching substrates was found to be necessary at lower fluences (1 3 J cm-') for the ...

2014 Mössbauer spectra of hydrous spinel iron oxide colloids and their evolution with thermal treatment have been interpreted using a modified Weiss local field model. It is found that interparticle interactions overcome the single particle anisotropy energy. Existence of a crystalline texture within aggregates is suggested. J. Physique Lett. 46 (1985) L-437 L-443 15 mm 1985, Classification Phy...

Single crystals of stoichiometric MgA1204 spine1 were neutron-irradiated to fluences (> 0.1 MeV) of 2.8 x loz5 n m-2 (1.5 dpa) at 1015 K and 1.9 x loz6 n m-2 (10 dpa) at 925 K and 1 100 K. The resulting point defect'aggregates were investigated using bright-field and weak-beam dark-field transmission electron microscopy. For the higher dose, faulted interstitial Frank dislocation loops were fou...