Long-term electrochemical performance of polymeric precursor-derived films of LaCoO 3 doped with Ca 2+ (LCC), instead of the larger Sr 2+ which segregates at the electrode surface forming oxides/hydroxides, was investigated in the present study. It was determined that pre-calcination at 800 °C (LCC02-800) resulted in a higher electrochemical performance but a poorer long-term stability than those pre-calcined at 700 °C (LCC02-700) or 900 °C (LCC02-900). Increasing Ca 2+ content (LCC04-800) enhanced the initial electrochemical performance slightly, while causing a much poorer long-term stability. Microstructural evolution analyses revealed that, although it had some impact on the initial and long-term performance of LCC electrodes, it was not the strongest influence. It was determined via XPS analyses that formation of CaO and CaO + La 2 O 3 layers at the LCC02-800 and LCC04-800 surfaces, respectively, accompanied by a decrease in the relative amounts of adsorbed oxygen species (corresponding to surface oxygen vacancies) caused a faster performance degradation in these samples than those pre-calcined at 700 or 900 °C. Eventually, only the surface cation ratio of LCC02-700 became close to the theoretical one after long-term operation.

Magnetic force microscopy (MFM) is a widespread technique for imaging magnetic structures with a resolution of some 10 nanometers. MFM can be calibrated to obtain quantitative (qMFM) spatially resolved magnetization data in units of A/m by determining the calibrated point spread function of the instrument, its instrument calibration function (ICF), from a measurement of a well-known reference sample. Beyond quantifying the MFM data, a deconvolution of the MFM image data with the ICF also corrects the smearing caused by the finite width of the MFM tip stray field distribution. However, the quality of the calibration depends critically on the calculability of the magnetization distribution of the reference sample. Here, we discuss a Ti/Pt/Co multilayer stack that shows a stripe domain pattern as a suitable reference material. A precise control of the fabrication process, combined with a characterization of the sample micromagnetic parameters, allows reliable calculation of the sample’s magnetic stray field, proven by a very good agreement between micromagnetic simulations and qMFM measurements. A calibrated qMFM measurement using the Ti/Pt/Co stack as a reference sample is shown and validated, and the application area for quantitative MFM measurements calibrated with the Ti/Pt/Co stack is discussed.

Pt(xÅ)/Co(5Å)/Pt(10Å) trilayer films were deposited on naturally oxidized Si(111) substrate to investigate Ti underlayer effect on PMA. A small amount of Ti underlayer promoted the magnetic anisotropy to a perpendicular direction for x=8Å and 10Å. Both GI XRD and STM results showed that the Ti underlayer manipulated the growth of trilayer film. The Pt particles preferably grow the neighborhood of the Ti cluster, giving rise to a relatively smooth layer with a fiber texture fcc (111) structure. By contrast, the absence of Ti underlayer leads to clustered, relatively rough, and randomly oriented nano-crystalline growth. Differences in the growth mode, especially roughness, also appeared as intensity loss in XPS spectra due to shadowing effects. Our results indicate that a traceable amount of underlayer can change the magnetic anisotropy of the film by manipulating film growth.

Magnetic force microscopy (MFM) is a widespread technique for imaging magnetic structures with a resolution of some 10 nanometers. MFM can be calibrated to obtain quantitative (qMFM) spatially resolved magnetization data in units of A/m by determining the calibrated point spread function of the instrument, its instrument calibration function (ICF), from a measurement of a well-known reference sample. Beyond quantifying the MFM data, a deconvolution of the MFM image data with the ICF also corrects the smearing caused by the finite width of the MFM tip stray field distribution. However, the quality of the calibration depends critically on the calculability of the magnetization distribution of the reference sample. Here, we discuss a Ti/Pt/Co multilayer stack which shows a stripe domain pattern as a suitable reference material. A precise control of the fabrication process combined with a characterization of the sample micromagnetic parameters allows to reliably calculate the sample’s magnetic stray field, proven by a very good agreement between micromagnetic simulations and qMFM measurements. A calibrated qMFM measurement using the Ti/Pt/Co stack as a reference sample is shown and validated and the application area for quantitative MFM measurements calibrated with the Ti/Pt/Co stack is discussed.