Study of the Internal Fields Acting on Iron Nuclei in Iron Garnets, Using the Recoil-Free Absorption inFe57of the 14.4-kev Gamma Radiation fromFe

Electromechanical properties of magnetite transducer

“…From our data of the electromechanical coupling factor of the present samples have high values of about 0.75 which is higher than that of the piezoelectric ceramic transducer and polymers [1][2][3]. These results are useful for introducing magnetite transducer as a good source for ultrasonic waves.…”

“…The conduction takes place through electron exchange Fe 2þ and Fe 3þ ions. The cation distribution of magnetite is [1][2][3] exchange interaction Fe 2þ and Fe 3þ are responsible for the polarization. The increase of temperature increases the polarization leading to increase the dielectric constant.…”

“…Magnetite, Fe 3 O 4 posses an inverse spinel structure [1][2][3] with the cation distribution ðFe 3þ 1 Þ A ½Fe 2þ 1 þFe 3þ 1 B O 2À 4 : For a binary oxide spinel containing divalent, x, and trivalent, y, cations, two extreme distributions of cations are possible: the normal ðxÞ½Y 2 O 4 and the inverse ðyÞ½xyO 4 distribution, where the ions present on the octahedral sites are in square brackets. The distributions between the two sites are possible depending upon temperature and impurities [4,5].…”

Mössbauer Effect forFe57in Ferroelectric BaTiO3. II. The Vacanc

“…This is because the isomer shift for Fe 3+ in this sample 5=0.34±0.05 mm/sec, closely corresponds with that for Fe 3 * in the tetrahedral sites of yttrium iron garnet. 22 Similarly low values of 8 and large values of / are obtainable from the data on trivalent iron in oxygendeficient perovskites, BaFeOa-* and SrFeOa-*. 23…”

Dependence of the Electrical Conductivity of Cobalt-Iron Oxides on γ-lrradiation Damage and Annealing

“…As indicated earlier, the cobalt-rich region (x > 1.0) has a normal [4] spinel structure and p-type [2] semiconducting behaviour, whereas the iron-rich region (x > 1.0) has inverse [3,9] spinel structure and n-type [2] semiconducting character. However, it was found that the conductivity, a, for all samples was increased by γ-irradiation (except for Fe304) where γ-irradiation can induce anionic vacancies together with electron-hole pairs which consequently will increase the probability of electron exchange on octahedral sites.…”