Although the search for new zeolites has traditionally been based on trial and error, more rational methods are now available. The theoretical concept of inverse σ transformation of a zeolite framework to generate a new structure by removal of a layer of framework atoms and contraction has for the first time been achieved experimentally. The reactivity of framework germanium atoms in strong mineral acid was exploited to selectively remove germanium-containing four-ring units from an UTL type germanosilicate zeolite. Annealing of the leached framework through calcination led to the new all-silica COK-14 zeolite with intersecting 12- and 10-membered ring channel systems. An intermediate stage of this inverse σ transformation with dislodged germanate four-rings still residing in the pores could be demonstrated. Inverse σ transformation involving elimination of germanium-containing structural units opens perspectives for the synthesis of many more zeolites.

The origin of the electric field-induced strain in the polycrystalline ceramic 0.92Bi 1/2 Na 1/2 TiO 3 -0.06BaTiO 3 -0.02K 1/2 Na 1/2 NbO 3 was investigated using in situ high-resolution X-ray and neutron diffraction techniques. The initially existing tetragonal phase with pseudocubic lattice undergoes a reversible phase transition to a significantly distorted rhombohedral phase under electric field, accompanied by a change in the oxygen octahedral tilting from a 0 a 0 c + to a À a À a À and in the tilting angle. The polarization values for the tetragonal and rhombohedral phases were calculated based on the structural information from Rietveld refinements. The large recoverable electric field-induced strain is a consequence of a reversible electric field-induced phase transition from an almost nonpolar tetragonal phase to a ferroelectrically active rhombohedral phase.

An in situ structural description of the origin of the ferroelectric properties as a function of the applied electric field E was obtained by synchrotron x-ray diffraction. A setup was used to average the effects of the preferred orientation induced by the strong piezoelectric strain and solve in situ the crystal structure as a function of the applied electric field. Hence, we were able to describe the microscopic origin of the macroscopic ferro- and piezoelectric properties of the most widely used ferroelectric material, lead zirconate titanate.

High energy density was achieved in lead-free La-doped AgNbO3 antiferroelectric ceramics.

1 Introduction The magnetocaloric effect [1,2] is the basis of an energy-efficient refrigeration technology, which has the potential to reduce the energy consumption of air conditioners, refrigerators and other domestic and industrial cooling applications [3]. The most promising magnetocaloric materials exhibit first-order magnetostructural or magnetovolume transitions, which lead to high adiabatic temperature changes in response to a changing external magnetic field. The transition temperatures of these firstorder transitions can be shifted towards room temperature by means of hydrogenation or doping [4]. However, large entropy and temperature changes can only be maintained if the first-order nature of the transition is kept [4].However, it has been shown for first-order-type magnetocaloric La(Fe,Si) 13 that when measuring the adiabatic temperature change ΔT ad , one needs to carefully distinguish between the first field cycle, which delivers a high adiabatic temperature change of ΔT ad = 7 K, and following cycles, in which it is reduced to ΔT ad = 5.8 K [5]. Similar findings have been reported for magnetocaloric Heuslers

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A brief review of in situ powder diffraction methods for battery materials is given. Furthermore, it is demonstrated that the new beamline P02.1 at the synchrotron source PETRA III (DESY, Hamburg), equipped with a new electrochemical test cell design and a fast two‐dimensional area detector, enables outstanding conditions for in situ diffraction studies on battery materials with complex crystal structures. For instance, the time necessary to measure a pattern can be reduced to the region of milliseconds accompanied by an excellent pattern quality. It is shown that even at medium detector distances the instrumental resolution is suitable for crystallite size refinements. Additional crucial issues like contributions to the background and available q range are determined.