Click to increase image sizeClick to decrease image size AcknowledgementsL. T. Ellis acknowledges the support of The Natural History Museum, London (BM). T. Kiebacher thanks J. Guerra for the confirmation of the determination of Tortula acaulon var. papillosa and var. retortifolia. The research of Denise Alvarez, Pablo G. Aceñolaza and Guillermo M. Suárez was sponsored by the Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), PIUNT G631 and PUE-CONICET 56 from Argentina. The study by Yu.S. Mamontov was supported by the Russian Ministry of Higher Education and Science with grant 075-15-2021-678 supporting the Center of Common Use «Herbarium MBG RAS» and within the State assignment (122042700002-6). R. D. Cedrés-Perdomo, D. Eiroa and A. Losada-Lima acknowledge the Garajonay National Park for providing permission to collect bryophyte specimens from La Gomera island. K. V. Lavrinenko thanks Anna Kuzemko, Yakiv Didukh, Оleksandr Khodosovtsev and Natalia Pashkevych for their substantial help in organising the expedition trip and conducting research. B. S. Cubas and J. Muñoz thank L. l. Sáez for donating the specimen of Macromitrium crosbyorum upon which their new record is based. Nik Norhazrina and Nur Syazwana would like to thank Mr Ahmad Damanhuri for confirming the identity of their new record for Leucobryum javense var. uncinatum. The research of Ilona Jukonienė was funded by the Administration of the Curonian Spit National Park (Agreement with Nature Research Centre VPS-23). J. Eckstein would like to thank Simona Strgulc Krajšek and Beata Papp for their help with his contribution. Joan Bruno Silva and Sérgio de Faria Lopes thank Dr Denilson Fernandes Peralta at the Botany Institute of São Paulo for confirming the identification of Myriocoleopsis minutissima. The study by V. E. Fedosov and A. S. Shkurko was supported by Russian scientific foundation grant # 23-14-00043. The contribution of S. Strgulc Krajšek, L. Kutnar and Marko Sabovljević was financially supported by The Slovenian Research Agency (grant no. P1-0212, P4-0107) and the EU Project LIFE, Integrated Project for Enhanced Management of Natura 2000 in Slovenia (LIFE17 IPE/SI/000011).

1. Andreaea flexuosa R.Br.bisContributor: H. Bednarek-OchyraChile: Isla Grande de Tierra del Fuego: Alberto de Agostini National Park, Monte Buckland, towering over a narrow peninsula between Agost...

1. Aneura pseudopinguis (Herzog) PocsContributor: K. HylanderEthiopia: Kaffa, Bonga, Gimbo, Meligawa, Barta forest, 3 km ENE of Bonga, moist Afromontane forest, among other bryophytes on dead wood,...

Emergent phenomena, including superconductivity and magnetism, found in the two-dimensional electron liquid (2-DEL) at the interface between the insulators lanthanum aluminate (LaAlO3) and strontium titanate (SrTiO3) distinguish this rich system from conventional 2D electron gases at compound semiconductor interfaces. The origin of this 2-DEL, however, is highly debated, with focus on the role of defects in the SrTiO3, while the LaAlO3 has been assumed perfect. Here we demonstrate, through experiments and first-principle calculations, that the cation stoichiometry of the nominal LaAlO3 layer is key to 2-DEL formation: only Al-rich LaAlO3 results in a 2-DEL. Although extrinsic defects, including oxygen deficiency, are known to render LaAlO3/SrTiO3 samples conducting, our results show that in the absence of such extrinsic defects an interface 2-DEL can form. Its origin is consistent with an intrinsic electronic reconstruction occurring to counteract a polarization catastrophe. This work provides insight for identifying other interfaces where emergent behaviours await discovery.

The in situ epitaxial growth of Bi-Sr-Ca-Cu-O films by molecular beam epitaxy (MBE) is reported. The suitability of ozone to the MBE growth of cuprate superconductors is discussed. Molecular beams of the constituents were periodically shuttered to grow various Bi2Sr2Can-1CunOx phases, including 2201, 2212,2223,2245, and layered mixtures of these phases. Using these techniques a superconducting film with TConset near 100 K and Tc (ρ=0) of 81 K was achieved under entirely MBE conditions (Pchamber≤xl0-4 Torr during growth and cooling). The films are smooth on an atomic scale. The results demonstrate the ability of shuttered MBE growth to selectively grow Bi2Sr2Can-1CunOx phases.

The disorder inherent to doping by cation substitution in the complex oxides can have profound effects on collective-ordered states. Here, we demonstrate that cation-site ordering achieved through digital-synthesis techniques can dramatically enhance the antiferromagnetic ordering temperatures of manganite films. Cation-ordered (LaMnO 3 ) m /(SrMnO 3 ) 2 m superlattices show Néel temperatures ( T N ) that are the highest of any La 1− x Sr x MnO 3 compound, ∼70 K greater than compositionally equivalent randomly doped La 1/3 Sr 2/3 MnO 3 . The antiferromagnetic order is A-type, consisting of in-plane double-exchange-mediated ferromagnetic sheets coupled antiferromagnetically along the out-of-plane direction. Through synchrotron X-ray scattering, we have discovered an in-plane structural modulation that reduces the charge itinerancy and hence the ordering temperature within the ferromagnetic sheets, thereby limiting T N . This modulation is mitigated and driven to long wavelengths by cation ordering, enabling the higher T N values of the superlattices. These results provide insight into how cation-site ordering can enhance cooperative behaviour in oxides through subtle structural phenomena.

Photoinduced magnetization dynamics is investigated in chemically ordered (LaMnO3)2n/(SrMnO3)n superlattices using the time-resolved magneto-optic Kerr effect. A monotonic frequency-field dependence is observed for the n=1 superlattice, indicating a single spin population consistent with a homogeneous hole distribution. In contrast, for n> or =2 superlattices, a large precession frequency is observed at low fields indicating the presence of an exchange torque in the dynamic regime. We attribute the emergence of exchange torque to the coupling between two spin populations-viscous and fast spins.

Polarized neutron reflectivity measurements of a ferromagnetic [(LaMnO3)(11.8)/(SrMnO3)(4.4)](6) superlattice reveal a modulated magnetic structure with an enhanced magnetization at the interfaces where LaMnO3 was deposited on SrMnO3 (LMO/SMO). However, the opposite interfaces (SMO/LMO) are found to have a reduced ferromagnetic moment. The magnetic asymmetry is accompanied by a corresponding asymmetry in the lateral structural roughness of the two interfaces observed via electron microscopy, with enhanced ferromagnetism present at the interfaces that are atomically smooth over tens of nanometers. This result demonstrates that atomic-scale roughness can destabilize interfacial phases in complex oxide heterostructures.

What happens to ferromagnetism at the surfaces and interfaces of manganites? With the competition between charge, spin, and orbital degrees of freedom, it is not surprising that the surface behaviour may be profoundly different to that of the bulk. Using a powerful combination of two surface probes, tunnelling and polarized x-ray interactions, this paper reviews our work on the nature of the electronic and magnetic states at manganite surfaces and interfaces. The general observation is that ferromagnetism is not the lowest energy state at the surface or interface, which results in a suppression or even loss of ferromagnetic order at the surface. Two cases will be discussed ranging from the surface of the quasi-2D bilayer manganite (La(2-2x)Sr(1+2x)Mn(2)O(7)) to the 3D perovskite (La(2/3)Sr(1/3)MnO(3))/SrTiO(3) interface. For the bilayer manganite, which is ferromagnetic and conducting in the bulk, these probes present clear evidence for an intrinsic insulating non-ferromagnetic surface layer atop adjacent subsurface layers that display the full bulk magnetization. This abrupt intrinsic magnetic interface is attributed to the weak inter-bilayer coupling native to these quasi-two-dimensional materials. This is in marked contrast to the situation for the non-layered manganite system (La(2/3)Sr(1/3)MnO(3)/SrTiO(3)), whose magnetization near the interface is less than half the bulk value at low temperatures and decreases with increasing temperature at a faster rate than that for the bulk.