Scientific Highlights 2016

22 August 2016
Sketch of a ferroic triangle showing the relation and techniques with which the ferroic orders, FM, AFM, and FE, and their mutual coupling have been established. The experimental techniques written in black letters (polarized neutron reflectometry, PNR; resonant soft x-ray diffraction, SXRD; x-ray diffraction, XRD) to identify ferroic properties have been reported elsewhere [22, 24]. Magnetization, susceptibility, μSR, neutron diffraction, and electrical polarization are reported.

Coexisting multiple order parameters in single-layer LuMnO3 films

Magnetoelectric multiferroics hold great promise for electrical control of magnetism or magnetic control of ferroelectricity. However, single phase ferroelectric materials with a sizeable ferromagnetic magnetization are rare. Here, we demonstrate that a single-phase orthorhombic LuMnO3 thin film features coexisting magnetic and ferroelectric orders. The temperature dependence of the different order parameters are presented with ferromagnetic order appearing below 100 K and thus at much higher temperatures than ferroelectricity or antiferromagnetism (TN, TFE ≤ 40K).

27 April 2016
SnO2 rLIFTed pixel printed onto a commercial MSGS sensor structure. (a) A too large SnO2 pixel leads to a negligible resistance between the heater and the IDT. (b) A SnO2 pixel deposited only onto the IDTs. No measurable resistance between the heater and the IDTs occurs and the sensor is thus functional.

Coexisting multiple order parameters in single-layer LuMnO3 films

Gas sensors based on tin oxide (SnO2) and palladium doped SnO2 (Pd:SnO2) active materials are fabricated by a laser printing method, i.e. reactive laser-induced forward transfer (rLIFT). Thin films from tin based metal-complex precursors are prepared by spin coating and then laser transferred with high resolution onto sensor structures. The devices fabricated by rLIFT exhibit low ppm sensitivity towards ethanol and methane as well as good stability with respect to air, moisture, and time. Promising results are obtained by applying rLIFT to transfer metal-complex precursors onto uncoated commercial gas sensors. We could show that rLIFT onto commercial sensors is possible if the sensor structures are reinforced prior to printing. The rLIFT fabricated sensors show up to 4 times higher sensitivities then the commercial sensors (with inkjet printed SnO2). In addition, the selectivity towards CH4 of the Pd:SnO2 sensors is significantly enhanced compared to the pure SnO2 sensors. Our results indicate that the reactive laser transfer technique applied here represents an important technical step for the realization of improved gas detection systems with wide-ranging applications in environmental and health monitoring control.