Atomic force microscope tips coated by the thermal evaporation of a magnetic 30 nm thick Co film have been modified by focused ion beam milling with Ga+ ions to produce tips suitable for magnetic force microscopy. Such tips possess a planar magnetic element with high magnetic shape anisotropy, an extremely high aspect ratio of greater than 30:1, and an end radius of less than 25 nm. These tips have been used in a commercial atomic force microscope under ambient conditions to obtain 30 nm resolution magnetic images of an established CoNi/Pt multilayer reference sample.

Abstrad-In this paper we report on a study of the magnetic properties of Co/Pt multilayer films. We have examined nucleation and domain wall pinning controlled materials and observe two distinct forms of behaviour in terms of the samples hysteresis loops. We interpret our data in terms of a two coercivity model and we report on the magnetic behaviour in terms of a detailed analysis of irreversible magnetisation changes obtained from the measurement of remanence curves. The domain structures in remanent states have been examined using an MFM and we find a correlation between domain size and shape and the form of the associated remanence curves.

The ATHENA (Advanced Telescope for High ENergy Astrophysics) mission studies and techno log y p reparat io n are c ontinuing to progress. The optics for this future space observatory is based on the Silicon Pore Op t ics (SPO), an d is being evolved in a joint effort by industry, research institutions and ESA.The SPO technology uses the superb properties of monocrystalline Silicon, and spins in technologie s developed fo r t h e s emiconductor industry, benefiting from excellent materials, processes and equipment. In a holistic approach the t echnical and programmatic challenges of the ATHENA optics are being addressed simultaneously. A co mp rehensiv e Technology Development Plan (TDP) was defined and is being implemented to develop this novel X-ray optics t echnology.The performance, environmental compatibility and serial automated production and testing are being addressed in parallel, aiming at the demonstration of the required technology readiness for the Athena M issio n A d opt ion Rev iew ( MAR) expected in 2022.

Athena will be the largest space-based x-ray telescope to be flown by the European Space Agency: its large 2.6 m diameter lens will use a revolutionary new modular technology, Silicon Pore Optics (SPO). The lens will consist of several hundreds of smaller x-ray lenslets, called mirror modules, which each consist of about 70 mirror pairs. Those mirror modules are arranged in circles in a large optics structure and will focus x-ray photons with an energy of 0.5 to 10 keV at a distance of 12 m onto the detectors of Athena. The point-spread function (PSF) of the optic shall achieve a halfenergy width (HEW) of 5" at an energy of 1 keV, with an effective area of about 1.4 m 2 , corresponding to several hundred m 2 of super-polished mirrors with a roughness of about 0.3 nm and a thickness of only 150 μm. SPO using the highest grade double-side polished 300 mm wafers commercially available, have been invented to enable such telescopes. SPO allows the cost-effective production of high-resolution, large area, x-ray optics, by using all the advantages that mono-crystalline silicon and the mass production processes of the semi-conductor industry provide. SPO has also shown to be a versatile technology that can be further developed for gamma-ray optics, medical applications and for material research. This paper will present the status of the technology and of the mass production capabilities, show latest performance results and discuss the next steps in the development.

In this paper we report upon a study of the magnetization reversal mechanisms in Co/Pt thin films at elevated temperatures. An alternating gradient force magnetometer has been modified in order to perform measurements at elevated temperatures. The data obtained from hysteresis loops and remanence curves measured at high temperature has been used to analyse reversal mechanisms which are discussed in terms of a well established two-coercivity model. The high sensitivity of the magnetic measurements reveal subtle temperature dependent changes in the magnetic characteristics of the films, which are attributed to thermally induced modifications of the energy barriers to magnetization reversal and film microstructure. The evolution of domain structure during reversal has been examined by magnetic force microscopy for a sample placed in varying remanent states at elevated temperatures and is found to correlate with the two-coercivity model. Additionally, a method by which samples may be demagnetized in situ at elevated temperatures is discussed along with domain wall motion induced by the stray field from magnetic force microscope tips.