The thin layers of ZnO and ZnO: Al (Al doped zinc oxide—AZO) were deposited by the atomic deposition layer (ALD) method on silicon and glass substrates. The structures were deposited using diethylzinc (DEZ) and deionized water as zinc and oxygen precursors. A precursor of trimethylaluminum (TMA) was used to introduce the aluminum dopant. The present study of ALD-deposited ZnO and AZO films was motivated by their applications in photovoltaics. We attempted to expose several properties of such films. Structural, optical (including ellipsometric measurements) and electrical investigations were performed. We discussed the relations between samples doped with different Al fractions and their properties.

In this work, we study magnetization switching induced by spin-orbit torque in $\mathrm{W}$ ($\mathrm{Pt}$)/$\mathrm{Co}$/$\mathrm{Ni}\mathrm{O}$ heterostructures with variable thickness of $\mathrm{W}$ and $\mathrm{Pt}$ heavy-metal layers, a perpendicularly magnetized $\mathrm{Co}$ layer, and an antiferromagnetic $\mathrm{Ni}\mathrm{O}$ layer. Using current-driven switching and magnetoresistance and anomalous-Hall-effect measurements, we determine the perpendicular and in-plane exchange-bias field. Several Hall-bar devices possessing in-plane exchange bias from both systems are selected and analyzed in relation to our analytical switching model of the critical current density as a function of $\mathrm{Pt}$ and $\mathrm{W}$ thickness, resulting in estimation of the effective spin Hall angle and perpendicular effective magnetic anisotropy. We demonstrate in both the $\mathrm{Pt}$/$\mathrm{Co}$/$\mathrm{Ni}\mathrm{O}$ system and the $\mathrm{W}$/$\mathrm{Co}$/$\mathrm{Ni}\mathrm{O}$ system deterministic $\mathrm{Co}$ magnetization switching without an external magnetic field, which is replaced by an in-plane exchange-bias field. Moreover, we show that due to a higher effective spin Hall angle in the $\mathrm{W}$-based system than in the $\mathrm{Pt}$-based system, the relative difference between the resistance states in the magnetization current switching to the difference between the resistance states in magnetic field switching determined by the anomalous Hall effect ($\mathrm{\Delta }R/\mathrm{\Delta }{R}_{\mathrm{AHE}}$) is about twice as high in $\mathrm{W}$-based devices than in $\mathrm{Pt}$-based devices, while the critical switching-current density in $\mathrm{W}$-based devices is 1 order lower than in $\mathrm{Pt}$-based devices. The current-switching stability and the training process are discussed in detail.

We present a detailed study of Ta/Ru-based buffers and their influence on features crucial from the point of view of applications of Magnetic Tunnel Junctions (MTJs) such as critical switching current and thermal stability. We study buffer/FeCoB/MgO/Ta/Ru and buffer/MgO/FeCoB/Ta/Ru layers, investigating the crystallographic texture, the roughness of the buffers, the magnetic domain pattern, the magnetic dead layer thickness, and the perpendicular magnetic anisotropy fields for each sample. Additionally, we examine the effect of the current induced magnetization switching for complete nanopillar MTJs with lateral dimensions of 270 × 180 nm. Buffer Ta 5/Ru 10/Ta 3 (thicknesses in nm), which has the thickest dead layer, exhibits a much larger thermal stability factor (63 compared to 32.5) while featuring a slightly lower critical current density value (1.25 MA/cm2 compared to 1.5 MA/cm2) than the buffer with the thinnest dead layer Ta 5/Ru 20/Ta 5. We can account for these results by considering the difference in damping which compensates for the difference in the switching barrier heights.

We investigated the dependence of tunnel magnetoresistance (TMR), the resistance area (RA) product, crystallographic structure, the interlayer exchange coupling (IEC) and the coercive (H_c) fields in Co₄₀Fe₄₀B₂₀/MgO/Co₄₀Fe₄₀B₂₀ exchange biased spin valves on the Ar partial pressure, in the range from 1 mTorr to 15 mTorr, during the MgO sputtering. For all the metallic layers a linear dynamic deposition (LDD) with a constant wafer velocity was used, whereas for the MgO deposition a LDD wedge technology with gradient velocity. The crystallographic texture of MgO(001), IEC and H_c fields, TMR and RA significantly depend on the Ar partial pressure. We found that high Ar partial pressure (above 5.6 mTorr) resulted in weaker (001) texture, lower interplanar distances of the MgO barrier and higher IEC field. Low Ar partial pressure gives smoother MgO surfaces and provides good barrier quality which results in higher TMR and RA values

In this paper, we discuss the structural and magnetic properties of Ta(d)/Co₄₀Fe₄₀B₂₀/MgO/Ta multilayers. The CoFeB wedge layer was deposited on three buffers differing in Ta layer thickness: d = 5, 10, and 15 nm. A structural analysis showed that the Ta seed-buffer of 5 nm was amorphous, whereas thicker Ta grew in a β-tetragonal disordered structure. X-ray reflectivity measurements revealed that the Ta/CoFeB interface roughness for annealed samples ranged from 0.55 to 0.67 nm for a sample with a 0.85 nm CoFeB layer and decreased to approximately 0.47 nm for thicker CoFeB layers, while the average interface CoFeB/MgO thickness was about 0.2–0.3 nm. The morphological roughness of the amorphous single 5 nm Ta layer was the lowest, whereas crystalline grains in thicker Ta buffers induced higher roughness. The 5 nm thick MgO layer exhibited a strong (001)-oriented texture, which was the highest for the smoothest 5 nm Ta buffer. The magnetic dead layer thickness for the annealed sample with a 15 nm Ta buffer was 0.39 nm and increased with the decrease in the Ta buffer thickness. Temperature-dependent measurements offered further insight into the diffusion processes and the formation of the magnetic dead layer (MDL) at the Ta/CoFeB interface.