Physics – Condensed Matter – Materials Science
Scientific paper
2008-03-18
Phys. Rev. Lett. 100, 165703 (2008)
Physics
Condensed Matter
Materials Science
Scientific paper
10.1103/PhysRevLett.100.165703
Ultraviolet-photoemission (UPS) measurements and supporting specific-heat, thermal-expansion, resistivity and magnetic-moment measurements are reported for the magnetic shape-memory alloy Ni$_2$MnGa over the temperature range $100K < T < 250K$. All measurements detect clear signatures of the premartensitic transition ($T_\mathrm{PM}\sim 247K$) and the martensitic transition ($T_\mathrm{M} \sim 196K$). Temperature-dependent UPS shows a dramatic depletion of states (pseudogap) at $T_\mathrm{PM}$ located 0.3eV below the Fermi energy. First-principles electronic structure calculations show that the peak observed at 0.3eV in the UPS spectra for $T > T_\mathrm{PM}$ is due to the Ni-d minority-spin electrons. Below $T_\mathrm{M}$ this peak disappears, resulting in an enhanced density of states at energies around 0.8eV. This enhancement reflects Ni-d and Mn-d electronic contributions to the majority-spin density of states and is accompanied by significant reconstruction of the Fermi surface.
Fisher Russell A.
Hults W. L.
Lashley J. C.
Littlewood Peter B.
Manosa Lluis
No associations
LandOfFree
Combined experimental and theoretical investigation of the premartensitic transition in Ni$_2$MnGa does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Combined experimental and theoretical investigation of the premartensitic transition in Ni$_2$MnGa, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Combined experimental and theoretical investigation of the premartensitic transition in Ni$_2$MnGa will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-322551