Applying a magnetic field to a ferromagnetic ${\mathrm{Ni}}_{50}{\mathrm{Mn}}_{34}{\mathrm{In}}_{16}$ alloy in the martensitic state induces a structural phase transition to the austenitic state. This is accompanied by a strain which recovers on removing the magnetic field, giving the system a magnetically superelastic character. A further property of this alloy is that it also shows the inverse magnetocaloric effect. The magnetic superelasticity and the inverse magnetocaloric effect in Ni-Mn-In and their association with the first-order structural transition are studied by magnetization, strain, and neutron-diffraction studies under magnetic field.

Materials prepared by chemical Li deintercalation with NO₂BF₄ from Li_1.20Mn_0.54Co_0.13Ni_0.13O₂ and chemical Li reinsertion with LiI show very similar chemical composition, oxidation state of each transition metal ion, structural properties and electrochemical performance to those of the material recovered after the 1^st electrochemical cycle. Investigations combining redox titration, magnetic measurement, neutron diffraction and chemical analyzes reveal that uncommon redox processes are involved during the first charge at high voltage and explain the charge overcapacity and large reversible discharge capacity obtained for this material. This further assesses our proposal that oxygen, in addition to nickel and cobalt, participates to the redox processes in charge: within the bulk oxygen is oxidized without oxygen loss, whereas at the surface oxygen is oxidized to O₂ and irreversibly lost from the structure. During the subsequent discharge, in addition to nickel, cobalt and oxygen, manganese is also slightly involved in the redox processes (reduction) to compensate for the initial surface oxygen loss.

The newly discovered superconductor FeSe_1−x (x≈ 0.08, T_c ^onset≈ 13.5 K at ambient pressure rising to 27 K at 1.48 GPa) exhibits a structural phase transition from tetragonal to orthorhombic below 70 K at ambient pressure—the crystal structure in the superconducting state shows remarkable similarities to that of the REFeAsO_1−xF_x (RE = rare earth) superconductors.

At low temperatures, a simple molecular crystal can shrink along one axis when heated and expand along it when compressed.

A first-principles-derived scheme that incorporates ferroelectric and antiferrodistortive degrees of freedom is developed to study finite-temperature properties of $\mathrm{Pb}({\mathrm{Zr}}_{1-x}{\mathrm{Ti}}_x){\mathrm{O}}_3$ solid solution near its morphotropic phase boundary. The use of this numerical technique (i) resolves controversies about the monoclinic ground state for some Ti compositions, (ii) leads to the discovery of an overlooked phase, and (iii) yields three multiphase points that are each associated with four phases. Additional neutron diffraction measurements strongly support some of these predictions.