Spin injection and detection in lanthanum- and niobium-doped SrTiO3 using the Hanle technique

Abstract

There has been much interest in the injection and detection of spin polarized carriers in semiconductors for the purposes of developing novel spintronic devices. Here we report the electrical injection and detection of spin-polarized carriers into Nb-doped strontium titanate (STO) single crystals and La-doped STO epitaxial thin films using MgO tunnel barriers and the three-terminal Hanle technique. Spin lifetimes of up to ~100 ps are measured at room temperature and vary little as the temperature is decreased to low temperatures. However, the mobility of the STO has a strong temperature dependence. This behavior and the carrier doping dependence of the spin lifetime suggest that the spin lifetime is limited by spin-dependent scattering at the MgO/STO interfaces, perhaps related to the formation of doping induced Ti3+. Our results reveal a severe limitation of the three-terminal Hanle technique for measuring spin lifetimes within the interior of the subject material.

13 pages, 6 figures

References in corpus (4)

• Magnetic effects at the interface between nonmagnetic oxides
• Electrical Detection of Spin Accumulation at a Ferromagnet-Semiconductor Interface
• Spin extraction theory and its relevance to spintronics
• Anomalous scaling of spin accumulation in ferromagnetic tunnel devices with silicon and germanium

Cited by in corpus (13)

• Physics of SrTiO${}_3$-based heterostructures and nanostructures: a review
• Quantum Materials for Spin and Charge Conversion
• Observation of Inverse Edelstein Effect in Rashba-Split 2DEG between SrTiO3 and LaAlO3 at Room Temperature
• Impurity-assisted tunneling magnetoresistance under weak magnetic field
• Emerging magnetism and electronic phase separation at titanate interfaces
• Electric Field Driven Memristive Behavior at the Schottky Interface of Nb doped SrTiO3
• Electric field control of spin lifetimes in Nb-SrTiO${}_3$ by spin-orbit fields
• Derivation of effective spin-orbit Hamiltonians and spin lifetimes, with application to SrTiO${}_3$ heterostructures
• Spin heat accumulation induced by tunneling from a ferromagnet
• Electric control of spin injection into a ferroelectric semiconductor
• Controlled formation of high-mobility shallow electron gases in SrTiO3 single crystal
• Spin injection via (110)-grown semiconductor barriers
• Non-linear spin transport in a rectifying ferromagnet/semiconductor Schottky contact