Itinerant U $5f$ band states in the layered compound ${\mathrm{UFeGa}}_5$ observed by soft x-ray angle-resolved photoemission spectroscopy

We have performed angle-resolved photoemission spectroscopy experiments on paramagnetic ${\mathrm{UFeGa}}_5$ using soft x-ray synchrotron radiation $(h\nu =500\mathrm{eV})$ and derived the bulk- and U $5f$-sensitive electronic structure of ${\mathrm{UFeGa}}_5$. Although the agreement between the experimental band structure and the local density approximation calculation treating U $5f$ electrons as being itinerant is qualitative, the morphology of the Fermi surface is well-explained by the calculation, suggesting that the U $5f$ states can be essentially understood within the itinerant-electron model.

Figure 1

(Color online) Valence-band spectra of ${\mathrm{UFeGa}}_5$ measured with $h\nu =400$, 500, and $800\mathrm{eV}$.

Figure 2

(Color online) (a) Position of ARPES cuts in $k$ space. ARPES spectra of ${\mathrm{UFeGa}}_5$ measured along (b) the $\mathrm{Z}$-$\mathrm{R}$ and (c) the $\mathrm{Z}$-$\mathrm{A}$ directions. The Brillouin zone is also indicated.

Figure 3

(Color) Band structure of ${\mathrm{UFeGa}}_5$ measured along (a) the $\mathrm{Z}$-$\mathrm{R}$ and (b) the $\mathrm{Z}$-$\mathrm{A}$ directions. Calculated energy band dispersions to be compared with the experiment along (c) the $\mathrm{Z}$-$\mathrm{R}$ and (d) the $\mathrm{Z}$-$\mathrm{A}$ directions are shown.

Figure 4

(Color) (a) Experimental Fermi surface of ${\mathrm{UFeGa}}_5$. (b) Calculated Fermi surface of ${\mathrm{UFeGa}}_5$ (solid lines) and ${\mathrm{ThFeGa}}_5$ (dotted lines) in the $\mathrm{Z}$-$\mathrm{R}$-$\mathrm{A}$ plane. (c) Calculated three-dimensional Fermi surface of ${\mathrm{UFeGa}}_5$.