Electrical control of magnetism via resistive switching in Pt/Mn₃O₄/Nb-doped SrTiO₃heterostructures

Annealing atmosphere effect on the resistive switching and magnetic properties of spinel Co3O4 thin films prepared by a sol–gel technique

“…9. 59,60,64 Usually, the oxygen vacancies can inevitably be introduced in Co 3 O 4 thin lm during deposition process. 65 The magnetism of thin lms increases by increasing the oxygen vacancy concentration.…”

“…65 The magnetism of thin lms increases by increasing the oxygen vacancy concentration. 60 Also, the ferromagnetic characteristics of lms can be created by cation disordering such as partial Co 2+ ions occupying the O h sites and displacement of some Co 3+ from the O h positions to the T d positions, and similar cases occurred in the Mn 3 O 4 and ZnFe 2 O 4 thin lms. 60 Thus, the super-exchange interactions between Co 2+ at T d and O h positions change the magnetic coupling of Co 2+ (T d )-Co 2+ (T d ) from antiferromagnetic to ferromagnetic characteristics.…”

“…60 Also, the ferromagnetic characteristics of lms can be created by cation disordering such as partial Co 2+ ions occupying the O h sites and displacement of some Co 3+ from the O h positions to the T d positions, and similar cases occurred in the Mn 3 O 4 and ZnFe 2 O 4 thin lms. 60 Thus, the super-exchange interactions between Co 2+ at T d and O h positions change the magnetic coupling of Co 2+ (T d )-Co 2+ (T d ) from antiferromagnetic to ferromagnetic characteristics. 44 However, aer electroforming process, a large number of oxygen vacancies can easily be induced by electrical impulse, 3 which results in lower saturation magnetization at fresh state than at HRS and LRS of Pt/Co 3 O 4 /Pt stack in Fig.…”

“…At the same time, oxygen ions are much more mobile than the cobalt cations and its migration jumps from the oxygen coordination in the lattice, which results in generation and accumulation of multiple oxygen vacancies. 60,66 Then, the oxygen vacancies based CFs are connected between the top electrode and bottom electrode. On increasing oxygen vacancy concentration, the Co 3+ ions occupying the O h positions are converted into Co 2+ ions, and the super-exchange interactions of Co 2+ (T d )-Co 2+ (T d ) are also enhanced, which results in the enhancement of saturation magnetization.…”

High performance, electroforming-free, thin film memristors using ionic Na0.5Bi0.5TiO3

“…13 While they can show intrinsically high ON/OFF ratio (Z10 4 ), and stable endurance or retention without degradation, a range of challenges still remain for these systems, e.g. the need for relatively large (50 nm and above) thickness of films, 29,30 high growth temperatures (700 1C and above 31,32 ), and often poor uniformity owing to uncontrolled defects. 13,33,34 In this report, we demonstrate the key materials parameters necessary to achieve high performance memristors.…”