Enhanced Orbital Torque Efficiency and Magnetization Switching Through <i>M</i> ( <i>M</i> = MgO, Gd, and Pt) Doping Ti Orbital Hall Channel for Efficient Orbitronic Devices

Abstract The orbital Hall effect in materials with weakly spin‐orbit coupling has attracted considerable interest for orbitronic applications due to its high efficiency, low cost, and environmental friendliness. Here, the enhanced orbital torque efficiency and magnetization switching of the Ti 1‐X M X ( M = MgO, Gd, and Pt)/[Co/Pt] 4 structures are systematically investigated. The absolute value of the orbital torque efficiencies is significantly improved up to ≈0.23, ≈0.20, and ≈0.27 with MgO, Gd, and Pt dopants, respectively, compared to the Ti/[Co/Pt] 4 matrix structure (≈0.06). Furthermore, the high orbital torque efficiencies lower the critical switching current density of 1.9 × 10 7 A cm −2 for Ti/[Co/Pt] 4 to 3.6 × 10 6 , 4.0 × 10 6 , and 7.8 × 10 6 A cm −2 for Ti 1‐X MgO X /[Co/Pt] 4 , Ti 1‐X Gd X /[Co/Pt] 4 , and Ti 1‐X Pt X /[Co/Pt] 4 structures, respectively. The enhancement of orbital torque efficiency of Ti 1‐X MgO X /[Co/Pt] 4 heterostructures mainly originates from the improvement of the resistivity of Ti 1‐X MgO X , and for Ti 1‐X Gd X /[Co/Pt] 4 and Ti 1‐X Pt X /[Co/Pt] 4 heterostructures, it can be dominantly attributed to the improvements of orbital Hall conductivity of Ti 1‐X Gd X and Ti 1‐X Pt X , verified through the first‐principles calculations. Our findings offer a promising approach for developing energy‐efficient orbitronic devices.