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1. Highly luminescent ultra-thin films with rare earth for plasmonic applications

   https://doi.org/10.1364/OPTCON.489698  

   Munga, J.; Yang, C.; Rab, Md_A; Shahbazyan, T_V; Durach, M.; Noginov, M_A; Noginova, N. (October 2023, Optics Continuum)

   Amphiphilic complexes with luminescent rare earth metal ions suitable for Lanmuir-Blodgett (LB) deposition have been synthesized. LB monolayers with closely packed Eu complexes deposited directly on silver demonstrate significant far-field emission in contrast to the theoretical predictions of full quenching. Angular radiation and polarization patterns of the electric and magnetic dipole emission of Eu³⁺point to a high excitation efficiency of surface plasmon polaritons. Different luminescent behavior of closely packed emitters in comparison to diluted systems is tentatively attributed to the collective state of emitters in LB layers formed via near-field coupling with surface plasmons. 

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2. New amphiphilic complexes with luminescent rare-earth ions

   https://doi.org/10.1557/s43580-025-01221-y  

   Jenkins, Jaycie; Johnson, Chantel; Wilson, Ashleigh_K; Munga, John; Yang, Chi; Noginova, Natalia (March 2025, MRS Advances)

   Abstract Organic compounds containing luminous rare-earth ions are of interest for numerous nanophotonic and plasmonic applications, including nanoscale lasers, biosensors, and optical magnetism studies. Optical studies of Eu³⁺complexes revealed that ultra-thin LB monolayers are highly luminescent even when deposited directly on plasmonic metal, which makes these materials very promising for plasmonic applications and studies, including control and enhancement of magnetic dipole emission with a plasmonic environment. In this work, we synthesize amphiphilic complexes with various rare-earth ions Nd³⁺, Yb³⁺, and DPT ligands and show that they all are suitable for monolayer or multilayer deposition with the Langmuir–Blodgett (LB) technique. Graphical abstract 

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3. Spin fluctuation driven magnetoresistance, domain Re-distribution and anomalous Hall effect in helical antiferromagnetic Eu metal thin films

   https://doi.org/10.1063/9.0000861  

   Shrestha, Narendra; Tang, Jinke (March 2025, AIP Advances)

   Europium (Eu) metal has a body centered cubic crystal structure which, upon a paramagnetic-to-helical magnetic phase transition, undergoes a body centered tetragonal distortion. The magnetic helix appears below a Néel temperature (TN) of ∼90 K, and an applied magnetic field gives rise to conical magnet structure. We have prepared Eu metal thin films on Si (001) substrates using Eu metal as a target by pulsed laser deposition and studied the transport properties by a four-probe method. The resistance shows a sudden slope change at TN of 88 K. The magnetoresistance (MR) is positive at temperatures below 30 K and exhibits negative values above that. Our analyses show that the positive MR at low temperatures originates from magnetic field induced spin fluctuation, and the negative MR at higher temperature is a result of suppression of critical spin fluctuation of the Eu spins by the magnetic field. The Eu film also shows hysteretic MR behaviors in mid field range, which is a result of re-distribution of the helical antiferromagnetic domains by the magnetic fields. We have also studied the transverse magnetotransport in the Eu thin films. The observed anomalous Hall effect is believed to be associated with the magnetic moment induced by the field or due to the helical spin structure of Eu itself. 

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4. Lanthanide Identity Governs Guest‐Induced Dimerization in Ln ^III [15‐MC _N(L‐pheHA) ‐5]) ³⁺ Metallacrowns

   https://doi.org/10.1002/chem.202103263  

   Sgarlata, Carmelo; Schneider, Bernadette_L; Zito, Valeria; Migliore, Rossella; Tegoni, Matteo; Pecoraro, Vincent_L; Arena, Giuseppe (November 2021, Chemistry – A European Journal)

   Abstract Series of lanthanide‐containing metallic coordination complexes are frequently presented as structurally analogous, due to the similar chemical and coordinative properties of the lanthanides. In the case of chiral (Ln^III[15‐MC_N(L‐pheHA)‐5])³⁺metallacrowns (MCs), which are well established supramolecular hosts, the formation of dimers templated by a dicarboxylate guest (muconate) in solution of neutral pH is herein shown to have a unique dependence on the identity of the MC's central lanthanide. Calorimetric data and nuclear magnetic resonance diffusion studies demonstrate that MCs containing larger or smaller lanthanides as the central metal only form monomeric host‐guest complexes whereas analogues with intermediate lanthanides (for example, Eu, Gd, Dy) participate in formation of dimeric host‐guest‐host compartments. The driving force for the dimerization event across the series is thought to be a competition between formation of highly stable MCs (larger lanthanides) and optimally linked bridging guests (smaller lanthanides). 

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5. Exploring few and single layer CrPS ₄ with near-field infrared spectroscopy

   https://doi.org/10.1088/2053-1583/abf251  

   Neal, Sabine N.; O’Neal, Kenneth R.; Haglund, Amanda V.; Mandrus, David G.; Bechtel, Hans A.; Carr, G. Lawrence; Haule, Kristjan; Vanderbilt, David; Kim, Heung-Sik; Musfeldt, Janice L. (April 2021, 2D Materials)

   Abstract We combine synchrotron-based near-field infrared spectroscopy and first principles lattice dynamics calculations to explore the vibrational response of CrPS₄in bulk, few-, and single-layer form. Analysis of the mode pattern reveals aC2 polar + chiral space group, no symmetry crossover as a function of layer number, and a series of non-monotonic frequency shifts in which modes with significant intralayer character harden on approach to the ultra-thin limit whereas those containing interlayer motion or more complicated displacement patterns soften and show inflection points or steps. This is different from MnPS₃where phonons shift as 1/size²and are sensitive to the three-fold rotation about the metal center that drives the symmetry crossover. We discuss these differences as well as implications for properties such as electric polarization in terms of presence or absence of the P–P dimer and other aspects of local structure, sheet density, and size of the van der Waals gap. 

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