Direct spectroscopic observation of a shallow hydrogenlike donor state in insulating SrTiO3.
We present a direct spectroscopic observation of a shallow hydrogenlike muonium state in SrTiO(3) which confirms the theoretical prediction that interstitial hydrogen may act as a shallow donor in this material. The formation of this muonium state is temperature dependent and appears below ∼ 70K. From the temperature dependence we estimate an activation energy of ∼ 50 meV in the bulk and ∼ 23 meV near the free surface. The field and directional dependence of the muonium precession frequencies further supports the shallow impurity state with a rare example of a fully anisotropic hyperfine tensor. From these measurements we determine the strength of the hyperfine interaction and propose that the muon occupies an interstitial site near the face of the oxygen octahedron in SrTiO(3). The observed shallow donor state provides new insight for tailoring the electronic and optical properties of SrTiO(3)-based oxide interface systems.
Paul Scherrer Institute, Laboratory for Muon Spin Spectroscopy, CH-5232 Villigen PSI, Switzerland.
Z
Z
Salman
Paul Scherrer Institute, Laboratory for Muon Spin Spectroscopy, CH-5232 Villigen PSI, Switzerland.
T
T
Prokscha
Paul Scherrer Institute, Laboratory for Muon Spin Spectroscopy, CH-5232 Villigen PSI, Switzerland.
A
A
Amato
Paul Scherrer Institute, Laboratory for Muon Spin Spectroscopy, CH-5232 Villigen PSI, Switzerland.
E
E
Morenzoni
Paul Scherrer Institute, Laboratory for Muon Spin Spectroscopy, CH-5232 Villigen PSI, Switzerland.
R
R
Scheuermann
Paul Scherrer Institute, Laboratory for Muon Spin Spectroscopy, CH-5232 Villigen PSI, Switzerland.
K
K
Sedlak
Paul Scherrer Institute, Laboratory for Muon Spin Spectroscopy, CH-5232 Villigen PSI, Switzerland.
A
A
Suter
D006859:Hydrogen / Q000737:chemistry*; D008651:Mesons; D008962:Models, Theoretical; D010087:Oxides / Q000737:chemistry*; D013057:Spectrum Analysis / Q000379:methods; D013324:Strontium / Q000737:chemistry*; D013816:Thermodynamics; D014025:Titanium / Q000737:chemistry*
D010087:Oxides; D006859:Hydrogen; D014025:Titanium; C119252:strontium titanium oxide; D013324:Strontium