Microstructure and local electrical behavior in [(Nd₂Ti₂O₇)₄/(SrTiO₃)_n]₁₀ (n = 4–8) superlattices

Abstract

Artificial [(Nd 2 Ti 2 O 7 ) 4 /(SrTiO 3 ) n ] 10 superlattices (n ¼ 4 and 8) were successfully epitaxially grown on SrTiO 3 substrates by pulsed laser deposition using the in situ high energy electron diffraction reflection diagnostic. Scanning transmission electron microscopy energy dispersive spectroscopy analysis showed the diffusion of Nd 3+ cations on Sr 2+ sites in SrTiO 3 structure into the multilayers, which was more pronounced when the value of n was lower. These particular nanoscale electrical behaviors, evidenced by electrical conducting channels and misleading PFM signals, were mainly attributed to the presence of oxygen vacancies in the SrTiO 3 layers at higher concentrations near the interface and to the mixed valence state of the titanium (Ti 3+ /Ti 4+ ). This work showed the strong influence of interface structure on nanoscale electrical phenomena in complex oxide superlattices.

Magnetic Micro and Nano Sensors for Continuous Health Monitoring

“…The idea of using La 0.7 Sr 0.3 MnO 3 as a thermometer was also discussed by Wu et al, who also measured the CMR effect of their samples, but did not mention its potential application in health monitoring [157]. Carlier et al mentioned that several perovskites showing CMR are lead-free which enables, in principle, their use in vivo, but without giving examples of their health monitoring applications [158]. Besides these and very similar studies, no mentions of health monitoring in correlation with CMR were found.…”