Structural properties of FCC and HCP phases in the Fe–Mn–Si system: A neutron diffraction experiment

Mn and Si influence on the hyperfine properties of the fcc and hcp phases in the Fe–Mn and Fe–Mn–Si systems

“…According to previous results obtained by neutron diffraction on the same set of samples [16], the a fcc , a hcp and c hcp lattice parameters of the fcc and hcp phases increase with Mn content whereas the Si addition produces an increment of c hcp and a decrement of a fcc and a hcp ones. These changes in the lattice parameters induce an increase of the unit cell volume of both phases with the Mn content and a decrease of the fcc phase unit cell with the Si addition.…”

“…The set of samples used in the present study was previously structurally characterized by neutron diffraction, using small pieces of material inside a rotating device to simulate a polycrystalline randomly oriented sample [16]. The lines associated to hcp and fcc phases were observed as well as those associated to the antiferomagnetic ordering in the alloys.…”

“…In this case, three magnetic hyperfine interactions were employed to account for this phase considering the presence of 0 Mn, 1 Mn and 2 Mn nearest neighbor atoms to the Fe in the bcc structure [20]. According to the neutron diffraction patterns [16], the central part of the low velocity spectra (Fig. 1) were reproduced with two hyperfine interactions (I 1 and I 2 ) associated to the fcc and hcp phases, respectively.…”

Enthalpy change of the hcp/fcc martensitic transformation in the Fe–Mn and Fe–Mn–Si systems

“…This choice is supported on the available data set [3,[10][11][12][13][14] that will allow us to test the previous thermodynamic description of the Gibbs energy of fcc and hcp-phases of the Fe-Mn and Fe-Mn-Si systems [4,5,9]. This description, obtained after a refinement of the parameters of the Redlich-Kister [15] model is done in terms of Gibbs energy functions [7,8].…”

“…the transformation. The experimental results are obtained using Differential Scanning Calorimetry together with Mössbauer spectroscopy, dilatometry and neutron diffraction results [11][12][13][14]. This new information on the enthalpy changes is analyzed using descriptions of the molar Gibbs energy, allowing us to validate the existing description for the Gibbs energy of the metaestables fcc-and hcpphases, of the Fe-Mn and Fe-Mn-Si systems [4].…”