Non-contact atomic force microscopy of an antiferromagnetic NiO(100) surface using a ferromagnetic tip

Characterizing nanoscale scanning probes using electron microscopy: A novel fixture and a practical guide

“…The repeatable positioning afforded by the multi-probe fixture described in this report enables reliable observation of nanoscale tip information even when zone axis information is unattainable. SPM studies often require coating commercial Si probes with thin layers of polycrystalline materials [33][34][35][36] or the entire probe may be composed entirely of such materials. 37,38 Consequently, the diffraction orientation technique discussed in Section V B cannot be used to align the imaging plane between multiple mountings (e.g., before and after testing in an AFM).…”

Searching atomic spin contrast on nickel oxide (001) by force microscopy

“…Previous atomically resolved imaging experiments of NiO surfaces all have parameters in the following ranges: oscillation amplitudes of several nm and cantilevers with k ≈ 40 N/m oscillating at frequencies of some hundreds of kHz [8,9,10,11,12,13,14]. Optimal signal-to-noise ratio is expected for oscillation amplitudes A ≈ λ [21], where λ is the range of the interaction that is to be probed.…”

“…Previous atomically resolved imaging experiments of NiO surfaces all have parameters in the following ranges: oscillation amplitudes of several nanometers and cantilevers with k Ϸ 40 N / m oscillating at frequencies of some hundreds of kilohertz. [9][10][11][12][13][14][15][16] Optimal signal-to-noise ratio is expected for oscillation amplitudes A Ϸ , 23 where is the range of the interaction that is to be probed. Because of stability requirements, k · A has to exceed a critical value 24 and a large stiffness is required for stable operation at small amplitudes.…”

“…Because of its magnetic properties, NiO is used as a pinning layer in spin valves and has been instrumental in the study of metal-insulator transitions [7]. Several groups have studied NiO (001) by atomic force microscopy and obtained atomic images of the surface [8,9,10,11] and performed spectroscopy [12,13,14], but a clear-cut proof of the expected spin contrast is lacking. It has been proposed that spin contrast can only be observed at very small tip-sample distances [15], but this distance regime is difficult to reach with conventional AFM with soft cantilevers (spring constant k ≈ 40 N/m) and large amplitudes (A ≈ 10 nm).…”

“…7 NiO has been studied by elevated-temperature scanning tunneling microscopy. 8 Several groups have studied NiO ͑001͒ by atomic force microscopy and obtained atomic images of the surface [9][10][11][12] and performed spectroscopy, [13][14][15] but a clear-cut proof of the expected spin contrast has been lacking until recently. 16 In this experiment, Kaiser et al provide a first experimental clue about the feasibility of exchange force microscopy that had been proposed almost a decade earlier.…”