The discovery of lead-free hybrid double perovskites provides a viable approach in the search for stable and environmentally benign photovoltaic materials as alternatives to lead-containing systems such as MAPbX 3 (X = Cl, Br, or I). Following our recent reports of (MA) 2 KBiCl 6 and (MA) 2 TlBiBr 6 , we have now synthesized a hybrid double perovskite, (MA) 2 AgBiBr 6 , that has a low band gap of 2.02 eV and is relatively stable and nontoxic. Its electronic structure and mechanical and optical properties are investigated with a combination of experimental studies and density functional theory calculations.

IN A SEARCH FOR LEAD-FREE MATERIALS THAT COULD BE USED AS ALTERNATIVES TO THE HYBRID PEROVSKITES, (MA)PbX 3 , in photovoltaic applications, we have discovered a hybrid double perovskite, (MA) 2 KBiCl 6 , which shows striking similarities to the lead analogues. Spectroscopic measurements and nanoindentation studies are combined with density functional calculations to reveal the properties of this interesting system.The light-harvesting, semiconducting hybrid inorganic-organic perovskites (HIOPs) have recently attracted a great deal of attention in the photovoltaic community, with their solar cell efficiencies rising from ~4% to over 20% in just six years. 1, 2 The most extensively studied materials are the lead-containing systems, APbX 3 , where A is alkyl ammonium cation (e.g. CH 3 NH 3 + (methylammonium, MA) or NH 2 CHNH 2 + (formamidinium, FA)) and X is Cl -, Bror I -. However, the toxicity of lead to the environment could become a major drawback in their commercialization and the quest for lead-free alternatives is therefore attracting a lot of attention. Other group IV metals such as Ge and Sn are being explored, but the chemical instability of Sn 2+ and Ge 2+ presents challenges for their practical utilization. 3,4 Alternatively, the replacement of Pb 2+ by isoelectronic ions also seems attractive because the strong light absorption and long carrier life-times exhibited by MAPbX 3 are believed to be related to the 6s 2 6p 0 electronic configuration of Pb 2+ . 5 While Tl + is also toxic, Bi 3+ is an interesting option because coordination complexes of bismuth are used in over-the-counter medicines such as Pepto-Bismol. 6 However, this strategy poses challenges because Bi 3+ has a different valence state from Pb 2+ and cannot therefore be simply substituted into phases such as (MA)PbX 3 . In the present work, we show that the incorporation of Bi 3+ into a HIOP can be achieved by synthesizing a hybrid double perovskite of general formula (MA) 2 M I M III X 6 .There has been significant recent progress in the incorporation of Bi 3+ into hybrid perovskiterelated halides. For example, (MA) 3 Bi 2 I 9 can be readily obtained by using a synthetic route analogous to that used for MAPbI 3 , 7 and an ammonium bismuth iodide phase, (NH 4 ) 3 Bi 2 I 9 , was recently reported to show a bandgap of 2.04eV. 8 A number of alkali metal systems of

Single-phase magnetoelectric multiferroics are ferroelectric materials that display some form of magnetism. In addition, magnetic and ferroelectric order parameters are not independent of one another. Thus, the application of either an electric or magnetic field simultaneously alters both the electrical dipole configuration and the magnetic state of the material. The technological possibilities that could arise from magnetoelectric multiferroics are considerable and a range of functional devices has already been envisioned. Realising these devices, however, requires coupling effects to be significant and to occur at room temperature. Although such characteristics can be created in piezoelectric-magnetostrictive composites, to date they have only been weakly evident in single-phase multiferroics. Here in a newly discovered room temperature multiferroic, we demonstrate significant room temperature coupling by monitoring changes in ferroelectric domain patterns induced by magnetic fields. An order of magnitude estimate of the effective coupling coefficient suggests a value of ~1 × 10−7 sm−1.

Worldwide, exploited marine fish stocks are under threat of collapse [1]. Although the drivers behind such collapses are diverse, it is becoming evident that failure to consider evolutionary processes in fisheries management can have drastic consequences on a species' long-term viability [2]. The European eel (Anguilla anguilla; Linnaeus, 1758) is no exception: not only does the steep decline in recruitment observed in the 1980s [3, 4] remain largely unexplained, the punctual detection of genetic structure also raises questions regarding the existence of a single panmictic population [5-7]. With its extended Transatlantic dispersal, pinpointing the role of ocean dynamics is crucial to understand both the population structure and the widespread decline of this species. Hence, we combined dispersal simulations using a half century of high-resolution ocean model data with population genetics tools. We show that regional atmospherically driven ocean current variations in the Sargasso Sea were the major driver of the onset of the sharp decline in eel recruitment in the beginning of the 1980s. The simulations combined with genotyping of natural coastal eel populations furthermore suggest that unexpected evidence of coastal genetic differentiation is consistent with cryptic female philopatric behavior within the Sargasso Sea. Such results demonstrate the key constraint of the variable oceanic environment on the European eel population.

Lough Neagh produces over 500 t of grown eel annually and employs 300 people fishing yellow and silver eel. Glass eel are transported upstream and stocked into the Lough. Since glass eel returns crashed in the 1980s, additional glass eel seed has been purchased from other fisheries. The fishery now faces ecological, social and economic pressures. Prices for the product have fallen; recruitment to the fishery has declined, and seed has decreased in availability and increased in price. Fishers are less inclined to take up the hard work required to make a living fishing eel and the fisher population is ageing. The European Commission has recognised the decline of eel and proposed emergency measures, which may further affect the viability of the fishery. The sustainability of the fishery is examined, based on the relationship between glass eel input and grown eel outputs over a period of 45 years, set against increasing environmental, socio-economic, and natural resource pressures. Spawning escapement of silver eel is estimated by mark-recapture experiments. K E Y W O R D S :Anguilla anguilla, eel, fishery management, stock recruitment.