Mössbauer Study of FerrimagneticFe7Se8

Abstract

Mossbauer spectra of ferrimagn«ic Fe7be, have been taken at various temperatures ranging from liquid-nitrogen temperature to the specimen's Neel point. Three sets of six-line hyperfine patterns were obtained and assigned to three magnetically nonequivalent sites of a superstructure of the crystal. Isomer shifts indicate nearly Fe'+ for all three sites. Change of sign of quadrupole splittings above and below 130'K were observed and may be interpreted to be due to the spin-rotation from c axis to c plane with increasing temperature. The Neel temperature was determined to be (447+ 1) 'K.

XRD, DSC, MS and RS studies of Fe75Se25 iron selenide prepared by mechano-synthesis

“…The single line representing the Fe 7 Se 8 phase showed an isomer upshift, reaching typical values reported for this phase [20,21]. Again, the inclusion of a doublet with relative absorption area of 6% was necessary to reproduce a central line.…”

“…Again, the inclusion of a doublet with relative absorption area of 6% was necessary to reproduce a central line. The parameters obtained for this doublet (shown in Table 1) were considerably different from those observed for N-FeSe phase after 3 and 10 h of milling, and they were compared with those given for other iron selenides [17][18][19][20][21]. It is interesting to note that there are a wide range of M .…”

Influence of substitutional disorder on the electrical transport and the superconducting properties of Fe1+zTe1−x−ySexSy

“…The other one, a low field contribution to the hyperfine distribution at RT which evolves to higher fields as lowering temperature, would agree with the spin reorientation corresponding to Fe 7 Se 8 . [22] This impurity fraction represents about 10% of Field-cooled (FC) magnetization measurements as a function of temperature at 100 G for samples S01 to S07 are shown in Fig. 4.…”

Structural, magnetic, and electronic properties of iron selenide Fe6-7Se8 nanoparticles obtained by thermal decomposition in high-temperature organic solvents

“…11 The magnetic structure of Fe 1-x X consists of ferromagnetic iron layers in the s plane which are antiferromagnetically coupled to each other along the c-axis. [12][13][14][15][16][17][18][19] The total magnetic moment M tot appears from the competition between magnetic moments of neighboring layers, and the material can be antiferromagnetic (AFM) or ferrimagnetic (FRM) depending on the value of moments of the corresponding layer-sublattices.…”