High field magnetic and Mössbauer studies in amorphous Fe-Er-B-Si alloys

Sperimagnetism in Fe78Er5B17and Fe64Er19B17metallic glasses: I. Moment values and non-collinear components

“…They have been described by a sperimagnetic structure [10] in which the magnetic moments on the iron atoms point in a random cone that is ferrimagnetically coupled to a random cone of erbium moments. The identification of || Er µ = 8.0 B in (Fe,Er)BSi glasses, (which is smaller than the absolute value Er µ = 9.0 B ), was originally interpreted as evidence that the erbium moments lay randomly on a cone with a fixed semi-vertex angle Er = cos -1 (8/9) = 27º to the applied field [5]. Such "empty cone" structures occur in some crystalline oxides [e.g.…”

“…The (Fe,Er) -based glasses also exhibit ferrimagnetic compensation as a function of composition [5,6] and temperature [6,9]. We therefore made a preliminary study of a The magnetisation data and its analysis using a phenomenological model, will be presented in Figure 1 of [9], including the field dependence of the magnetisation.…”

“…These non spin-flip cross-sections of the (Fe,Tb) 83 B 17 glasses were nevertheless successfully simulated, by using a combination of known and derived partial structure factors [4]. Magnetisation, Mössbauer spectroscopy and X-ray magnetic circular dichroism (XMCD) measurements on (Fe,Er)BSi glasses [5]; amorphous FeEr alloys [6,7,8] and a single Fe 66 Er 19 B 15 glass [9], suggest that (Fe,Er) 83 B 17 are non-collinear ferrimagnets. They have been described by a sperimagnetic structure [10] in which the magnetic moments on the iron atoms point in a random cone that is ferrimagnetically coupled to a random cone of erbium moments.…”

Sperimagnetism in Fe78Er5B17and Fe64Er19B17metallic glasses: II. Collinear components and ferrimagnetic compensation

“…It is difficult therefore, to find the unique choice of the components of the moments, even from a combination of different bulk measurements [4,5,6,7,8]. …”

“…The related (Fe,Er) 83 B 17 glass have been shown to be a non-collinear ferrimagnets by a variety of different measurements [4,5,6,7,8], but our preliminary neutron scattering measurements on a Fe 64 Er 19 B 17 glass at 1.5K, 60K and 180K proved to be difficult to interpret [9]. The finite spin-flip cross-sections confirmed the presence of a non-collinear state and could be analysed using a sperimagnetic structure in which the magnetic moments on the iron atoms point in a random cone that is ferrimagnetically coupled to a random cone of erbium moments.…”