Limits...
Ferromagnetism of Fe3Sn and alloys.

Sales BC, Saparov B, McGuire MA, Singh DJ, Parker DS - Sci Rep (2014)

Bottom Line: We used first principles calculations to investigate the effect of elemental substitutions.However, transition metal substitutions with Co or Mn do not have this effect.We attempted synthesis of a number of these alloys and found results in accord with the theoretical predictions for those that were formed.

View Article: PubMed Central - PubMed

Affiliation: Materials Science and Technology Division, Oak Ridge National Laboratory.

ABSTRACT
Hexagonal Fe(3)Sn has many of the desirable properties for a new permanent magnet phase with a Curie temperature of 725 K, a saturation moment of 1.18 MA/m. and anisotropy energy, K1 of 1.8 MJ/m(3). However, contrary to earlier experimental reports, we found both experimentally and theoretically that the easy magnetic axis lies in the hexagonal plane, which is undesirable for a permanent magnet material. One possibility for changing the easy axis direction is through alloying. We used first principles calculations to investigate the effect of elemental substitutions. The calculations showed that substitution on the Sn site has the potential to switch the easy axis direction. However, transition metal substitutions with Co or Mn do not have this effect. We attempted synthesis of a number of these alloys and found results in accord with the theoretical predictions for those that were formed. However, the alloys that could be readily made all showed an in-plane easy axis. The electronic structure of Fe(3)Sn is reported, as are some are magnetic and structural properties for the Fe(3)Sn(2), and Fe(5)Sn(3) compounds, which could be prepared as mm-sized single crystals.

No MeSH data available.


Magnetization versus applied field for oriented Fe3Sn powder, and a polycrystalline Fe3Sn sample.Using the x-ray density of Fe3Sn, the room temperature saturation moment is 1.18 MA/m, or about 2.37 μB/Fe. Noting that the magnetization curves merged together near 3 Tesla, indicates a value for K1 of about 1.8 MJ/m.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4228330&req=5

f4: Magnetization versus applied field for oriented Fe3Sn powder, and a polycrystalline Fe3Sn sample.Using the x-ray density of Fe3Sn, the room temperature saturation moment is 1.18 MA/m, or about 2.37 μB/Fe. Noting that the magnetization curves merged together near 3 Tesla, indicates a value for K1 of about 1.8 MJ/m.

Mentions: A rough estimate of the anisotropy energy, K1, can be obtained from a comparison of magnetization curves from Fe3Sn powder oriented along the easy and hard directions. These data are shown in Figure 4. Using the approximation that K1 ≈ HaMs/2, with Ha ≈ 3 Tesla (the field at which the magnetization curves along the easy and hard directions merge), Ms = 1.18 MA/m yields 1.8 MJ/m3. The experimental magnitude of K1 is reasonably large but has the wrong sign (easy axis in plane rather than along c). Magnetization data versus temperature (300-2 K) from polycrystalline Fe3Sn in various applied magnetic fields (not shown) gave no indication of a change of the easy axis with temperature. This experimental estimate of K1 is remarkably close to the theoretical prediction of 1.59 MJ/m3 given above.


Ferromagnetism of Fe3Sn and alloys.

Sales BC, Saparov B, McGuire MA, Singh DJ, Parker DS - Sci Rep (2014)

Magnetization versus applied field for oriented Fe3Sn powder, and a polycrystalline Fe3Sn sample.Using the x-ray density of Fe3Sn, the room temperature saturation moment is 1.18 MA/m, or about 2.37 μB/Fe. Noting that the magnetization curves merged together near 3 Tesla, indicates a value for K1 of about 1.8 MJ/m.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4228330&req=5

f4: Magnetization versus applied field for oriented Fe3Sn powder, and a polycrystalline Fe3Sn sample.Using the x-ray density of Fe3Sn, the room temperature saturation moment is 1.18 MA/m, or about 2.37 μB/Fe. Noting that the magnetization curves merged together near 3 Tesla, indicates a value for K1 of about 1.8 MJ/m.
Mentions: A rough estimate of the anisotropy energy, K1, can be obtained from a comparison of magnetization curves from Fe3Sn powder oriented along the easy and hard directions. These data are shown in Figure 4. Using the approximation that K1 ≈ HaMs/2, with Ha ≈ 3 Tesla (the field at which the magnetization curves along the easy and hard directions merge), Ms = 1.18 MA/m yields 1.8 MJ/m3. The experimental magnitude of K1 is reasonably large but has the wrong sign (easy axis in plane rather than along c). Magnetization data versus temperature (300-2 K) from polycrystalline Fe3Sn in various applied magnetic fields (not shown) gave no indication of a change of the easy axis with temperature. This experimental estimate of K1 is remarkably close to the theoretical prediction of 1.59 MJ/m3 given above.

Bottom Line: We used first principles calculations to investigate the effect of elemental substitutions.However, transition metal substitutions with Co or Mn do not have this effect.We attempted synthesis of a number of these alloys and found results in accord with the theoretical predictions for those that were formed.

View Article: PubMed Central - PubMed

Affiliation: Materials Science and Technology Division, Oak Ridge National Laboratory.

ABSTRACT
Hexagonal Fe(3)Sn has many of the desirable properties for a new permanent magnet phase with a Curie temperature of 725 K, a saturation moment of 1.18 MA/m. and anisotropy energy, K1 of 1.8 MJ/m(3). However, contrary to earlier experimental reports, we found both experimentally and theoretically that the easy magnetic axis lies in the hexagonal plane, which is undesirable for a permanent magnet material. One possibility for changing the easy axis direction is through alloying. We used first principles calculations to investigate the effect of elemental substitutions. The calculations showed that substitution on the Sn site has the potential to switch the easy axis direction. However, transition metal substitutions with Co or Mn do not have this effect. We attempted synthesis of a number of these alloys and found results in accord with the theoretical predictions for those that were formed. However, the alloys that could be readily made all showed an in-plane easy axis. The electronic structure of Fe(3)Sn is reported, as are some are magnetic and structural properties for the Fe(3)Sn(2), and Fe(5)Sn(3) compounds, which could be prepared as mm-sized single crystals.

No MeSH data available.