Strain relaxation mechanisms of elastic softening and twin wall freezing associated with structural phase transitions in (Ca,Sr)TiO3 perovskites.

Resonant ultrasound spectroscopy has been used to measure the bulk modulus (K), shearmodulus (G) and acoustic dissipation of polycrystalline perovskite samples across theCaTiO(3)–SrTiO(3) solid solution in the temperature range ∼10–1350 K. A remarkable pattern of up to ∼25% softening of G as a function of both temperature and composition is due to coupling of shear strain with order parameters for the Pm3m ↔ I 4/mcm, I 4/mcm↔Pnmaand I 4/mcm↔Pbcm transitions. Anomalies in K associated with the phase transitions are small, consistent with only weak coupling of octahedral tilting order parameter(s) with volume strain.

MnSb2O6: a polar magnet with a chiral crystal structure.

Structural and magnetic chiralities are found to coexist in a small group of materials in which they produce intriguing phenomenologies such as the recently discovered Skyrmion phases. Here, we describe a previously unknown manifestation of this interplay in MnSb(2)O(6), a trigonal oxide with a chiral crystal structure. Unlike all other known cases, the MnSb(2)O(6) magnetic structure is based on corotating cycloids rather than helices.

Magneto-orbital helices as a route to coupling magnetism and ferroelectricity in multiferroic CaMn₇O₁₂.

Orbital physics drives a rich phenomenology in transition-metal oxides, providing the microscopic underpinning for effects such as Colossal Magnetoresistance. In particular, magnetic and lattice degrees of freedom are coupled through orbital ordering, and it has long been hoped that this coupling could be exploited to create high-temperature multiferroics with large values of the electrical polarization. Here we report an unprecedented magneto-orbital texture in multiferroic CaMn(7)O(12), found to give rise to the largest magnetically induced ferroelectric polarization measured to date.

Caesarean section scar ectopic pregnancy following postcoital contraception.

This is believed to be the first reported case of an ectopic pregnancy following failed progestogen-only emergency contraception. The ectopic pregnancy was at the site of a previous caesarean section scar and was managed conservatively.