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All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Er(AlFe)6 by Materials Project

ErFe6Al6 crystallizes in the orthorhombic Immm space group. The structure is three-dimensional. Er is bonded in a 8-coordinate geometry to twelve Fe and eight Al atoms. There are four shorter (3.22 Å) and eight longer (3.27 Å) Er–Fe bond lengths. There are a spread of Er–Al bond distances ranging from 2.85–2.99 Å. There are two inequivalent Fe sites. In the first Fe site, Fe is bonded in a 12-coordinate geometry to two equivalent Er, four Fe, and six Al atoms. All Fe–Fe bond lengths are 2.49 Å. There are two shorter (2.51 Å) and four longer (2.59 Å) Fe–Al bond lengths. In the second Fe site, Fe is bonded to two equivalent Er, four equivalent Fe, and six Al atoms to form a mixture of distorted corner, edge, and face-sharing FeEr2Al6Fe4 cuboctahedra. There are two shorter (2.58 Å) and four longer (2.62 Å) Fe–Al bond lengths. There are three inequivalent Al sites. In the first Al site, Al is bonded in a 10-coordinate geometry to one Er, six Fe, and three Al atoms. There are one shorter (2.66 Å) and two longer (2.82 Å) Al–Al bond lengths. In the second Al site, Al is bonded in a 8-coordinate geometry to one Er, six Fe, and one Al atom. The Al–Al bond length is 2.78 Å. In the third Al site, Al is bonded in a 12-coordinate geometry to two equivalent Er, six Fe, and two equivalent Al atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Epitaxial strain tuning of Er 3+ in ferroelectric thin films

Er 3+ color centers are promising candidates for quantum science and technology due to their long electron and nuclear spin coherence times, as well as their desirable emission wavelength. By selecting host materials with suitable, controllable properties, we introduce new parameters that can be used to tailor the Er 3+ emission spectrum. PbTiO 3 is a well-studied ferroelectric material with known methods of engineering different domain configurations through epitaxial strain. By distorting the structure of Er 3+ -doped PbTiO 3 thin films, we can manipulate the crystal fields around the Er 3+ dopant. This is resolved through changes in the Er 3+ resonant fluorescence spectra, tying the optical properties of the defect directly to the domain configurations of the ferroelectic matrix. Additionally, we are able to resolve a second set of peaks for films with in-plane ferroelectric polarization. We hypothesize these results to be due to either the Er 3+ substituting different sites of the PbTiO 3 crystal, differences in charges between the Er 3+ dopant and the original substituent ion, or selection rules. Systematically studying the relationship between the Er 3+ emission and the epitaxial strain of the ferroelectric matrix lays the pathway for future optical studies of spin manipulation by altering ferroelectric order parameters.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Stability, electronic quantum states, and magnetic interactions of Er 3+ ions in Ga 2 ⁢O 3

Here, we report an ab initio study of phase stability, defect formation, electronic structure, and multiple magnetic, Dzyaloshinskii-Moriya, optical, hyperfine, and crystal field interactions in erbium (Er)-doped wide band gap 𝛼- and 𝛽-gallium oxides (Ga 2 ⁢O 3 ), critically important to make a foundation for both optoelectronic and quantum information applications. The chemical, structural, mechanical, and dynamical stabilities of the pristine phases are confirmed from respective negative formation energies, negative cohesive energies, favorable elastic constants, and positive phonon frequencies. The phonon dispersions indicate that the Ga-O bonds are uniform in the 𝛼-phase, while they vary in the 𝛽-phase due to the anisotropic polyhedral movement. The defect formation energy analysis confirms that both Er-doped 𝛼- and 𝛽−Ga 2 ⁢O 3 prefer Er 3+ (neutral) state. The underestimated band gaps of the pristine phases from standard density functional theory (DFT) calculations as compared to experimental values are corrected by employing the hybrid functional calculations, resulting in the indirect band gaps of 5.21 eV in 𝛼−Ga 2 ⁢O 3 and 4.94 eV in 𝛽−Ga 2 ⁢O 3 . The site preference energy analysis indicates partial occupation of Er in the octahedral site of Ga. The anisotropic nature of hyperfine tensor coefficients of Er is similar in both phases, which may be due to the occupation of Er in the same octahedral Ga site. On the other hand, the calculated magnetic exchange interaction between two Er dopants is negative for 𝛼 and positive for 𝛽, indicating an antiferromagnetic (AFM) ground state in the former and a ferromagnetic (FM) ground state in the latter. Large values of Dzyaloshinskii-Moriya interactions (DMIs) are obtained along the 𝑥 direction in the 𝛼 and along the 𝑦 direction in the 𝛽. The large DMI may support exotic magnetic textures, a promising direction for spintronic applications. The analysis of dielectric constants and refractive indices of both pristine and Er-doped phases shows a good agreement with available experimental values. The calculated optical anisotropy is slightly higher in 𝛽 than those in 𝛼, which is due to the involvement of lower symmetry in 𝛽. The crystal field coefficients (CFCs) calculated from DFT are used to analyze 4⁢𝑓 multiplets and 4⁢𝑓 −4⁢𝑓 transitions. Thus calculated lowest energy level of the first excited state to the lowest energy level of the ground state is about 1.53 µ⁢m, which is in a good agreement with available experiments, and it falls within the quantum telecommunication wavelength range.

3-dimensional systems↗
DOE OSTI2020

Materials Data on Er(SiNi5)2 by Materials Project

ErNi10Si2 crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. Er is bonded in a 12-coordinate geometry to sixteen Ni and four equivalent Si atoms. There are a spread of Er–Ni bond distances ranging from 2.87–3.06 Å. All Er–Si bond lengths are 3.16 Å. There are three inequivalent Ni sites. In the first Ni site, Ni is bonded to two equivalent Er, eight Ni, and two equivalent Si atoms to form NiEr2Si2Ni8 cuboctahedra that share corners with six equivalent SiEr2Ni10 cuboctahedra, corners with twelve NiEr2Si2Ni8 cuboctahedra, edges with four equivalent NiEr2Si2Ni8 cuboctahedra, edges with four equivalent SiEr2Ni10 cuboctahedra, faces with two equivalent SiEr2Ni10 cuboctahedra, and faces with twelve NiEr2Si2Ni8 cuboctahedra. There are four shorter (2.41 Å) and four longer (2.47 Å) Ni–Ni bond lengths. Both Ni–Si bond lengths are 2.33 Å. In the second Ni site, Ni is bonded to two equivalent Er, eight Ni, and two equivalent Si atoms to form distorted NiEr2Si2Ni8 cuboctahedra that share corners with four equivalent SiEr2Ni10 cuboctahedra, corners with fourteen NiEr2Si2Ni8 cuboctahedra, edges with two equivalent SiEr2Ni10 cuboctahedra, edges with five NiEr2Si2Ni8 cuboctahedra, faces with four equivalent SiEr2Ni10 cuboctahedra, and faces with eleven NiEr2Si2Ni8 cuboctahedra. There are a spread of Ni–Ni bond distances ranging from 2.52–2.60 Å. Both Ni–Si bond lengths are 2.31 Å. In the third Ni site, Ni is bonded in a 12-coordinate geometry to one Er, eleven Ni, and two equivalent Si atoms. There are a spread of Ni–Ni bond distances ranging from 2.40–2.97 Å. Both Ni–Si bond lengths are 2.51 Å. Si is bonded to two equivalent Er and ten Ni atoms to form distorted SiEr2Ni10 cuboctahedra that share corners with four equivalent SiEr2Ni10 cuboctahedra, corners with fourteen NiEr2Si2Ni8 cuboctahedra, edges with eight NiEr2Si2Ni8 cuboctahedra, faces with four equivalent SiEr2Ni10 cuboctahedra, and faces with ten NiEr2Si2Ni8 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Er(Al2Mo)2 by Materials Project

Er(MoAl2)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Er is bonded in a 4-coordinate geometry to twelve Al atoms. There are four shorter (2.91 Å) and eight longer (3.25 Å) Er–Al bond lengths. Mo is bonded in a 10-coordinate geometry to two equivalent Mo and eight Al atoms. Both Mo–Mo bond lengths are 2.67 Å. All Mo–Al bond lengths are 2.78 Å. There are four inequivalent Al sites. In the first Al site, Al is bonded in a 11-coordinate geometry to three equivalent Er, four equivalent Mo, and four Al atoms. There are two shorter (2.62 Å) and two longer (2.87 Å) Al–Al bond lengths. In the second Al site, Al is bonded in a 11-coordinate geometry to three equivalent Er, four equivalent Mo, and four Al atoms. Both Al–Al bond lengths are 2.62 Å. In the third Al site, Al is bonded in a 11-coordinate geometry to three equivalent Er, four equivalent Mo, and four Al atoms. There are one shorter (2.62 Å) and two longer (2.87 Å) Al–Al bond lengths. In the fourth Al site, Al is bonded in a 11-coordinate geometry to three equivalent Er, four equivalent Mo, and four Al atoms. The Al–Al bond length is 2.62 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Er(ClO2)3 by Materials Project

Er(O2Cl)3 crystallizes in the monoclinic P2/c space group. The structure is two-dimensional and consists of one Er(O2Cl)3 sheet oriented in the (0, 1, 0) direction. Er is bonded in a distorted octahedral geometry to six O atoms. All Er–O bond lengths are 2.25 Å. There are three inequivalent O sites. In the first O site, O is bonded in a bent 150 degrees geometry to one Er and one Cl atom. The O–Cl bond length is 1.57 Å. In the second O site, O is bonded in a bent 120 degrees geometry to one Er and one Cl atom. The O–Cl bond length is 1.58 Å. In the third O site, O is bonded in a bent 150 degrees geometry to one Er and one Cl atom. The O–Cl bond length is 1.57 Å. There are two inequivalent Cl sites. In the first Cl site, Cl is bonded in a bent 120 degrees geometry to two O atoms. In the second Cl site, Cl is bonded in a water-like geometry to two equivalent O atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Er(SiPt)2 by Materials Project

ErPt2Si2 crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. Er is bonded in a 12-coordinate geometry to eight Pt and eight Si atoms. There are four shorter (3.19 Å) and four longer (3.27 Å) Er–Pt bond lengths. There are four shorter (3.17 Å) and four longer (3.22 Å) Er–Si bond lengths. There are two inequivalent Pt sites. In the first Pt site, Pt is bonded to four equivalent Er and four equivalent Si atoms to form distorted PtEr4Si4 tetrahedra that share corners with twelve equivalent SiEr4Pt4 tetrahedra, edges with two equivalent SiEr4Pt4 tetrahedra, edges with four equivalent PtEr4Si4 tetrahedra, and faces with four equivalent PtEr4Si4 tetrahedra. All Pt–Si bond lengths are 2.48 Å. In the second Pt site, Pt is bonded in a 9-coordinate geometry to four equivalent Er and five Si atoms. There are one shorter (2.37 Å) and four longer (2.43 Å) Pt–Si bond lengths. There are two inequivalent Si sites. In the first Si site, Si is bonded to four equivalent Er and four equivalent Pt atoms to form distorted SiEr4Pt4 tetrahedra that share corners with twelve equivalent PtEr4Si4 tetrahedra, edges with two equivalent PtEr4Si4 tetrahedra, edges with four equivalent SiEr4Pt4 tetrahedra, and faces with four equivalent SiEr4Pt4 tetrahedra. In the second Si site, Si is bonded in a 9-coordinate geometry to four equivalent Er and five Pt atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2026

Er Al :Al 2 ⁢O 3 for telecom-band photonics: Electronic structure and optical properties

Er-doped Al 2 ⁢O 3 is a promising host for telecom-band integrated photonics. Here, in this study, we combine ab initio calculations with a symmetry-resolved analysis to elucidate substitutional Er on the Al site (Er Al ) in 𝛼−Al 2 ⁢O 3 . First-principles relaxations confirm the structural stability of Er Al . We then use the local trigonal crystal-field symmetry to classify the Er-derived impurity levels by irreducible representations and to derive polarization-resolved electric-dipole selection rules, explicitly identifying the symmetry-allowed 𝑓−𝑑 hybridization channels. Kubo-Greenwood absorption spectra computed from Kohn-Sham states quantitatively corroborate these symmetry predictions. Furthermore, we connect the calculated intra-4⁢𝑓 line strengths to Judd-Ofelt theory, clarifying the role of 4⁢𝑓−5⁢𝑑 admixture in enabling optical activity. Notably, we predict a characteristic absorption near 1.47 µ⁢m (telecom band), relevant for on-chip amplification and emission. To our knowledge, a symmetry-resolved first-principles treatment of Er:Al 2 ⁢O 3 with an explicit Judd-Ofelt interpretation has not been reported, providing a transferable framework for tailoring rare-earth dopants in wide-band-gap oxides for integrated photonics. Our results for the optical spectra are in good agreement with experimental data. The resulting symmetry-based selection rules translate directly to polarization-dependent coupling in Al 2 ⁢O 3 integrated photonic waveguides and resonators, enabling device-level design of TE/TM-mode interaction with Er emitters in the 1.5-µ⁢m telecom band.

Er-doped Al2O3↗
DOE OSTI2021

Revealing functional insights into ER proteostasis through proteomics and interactomics

The endoplasmic reticulum (ER), responsible for processing approximately one-third of the human proteome including most secreted and membrane proteins, plays a pivotal role in protein homeostasis (proteostasis). Dysregulation of ER proteostasis has been implicated in a number of disease states. As such, continued efforts are directed at elucidating mechanisms of ER protein quality control which are mediated by transient and dynamic protein-protein interactions with molecular chaperones, co-chaperones, protein folding and trafficking factors that take place in and around the ER. Technological advances in mass spectrometry have played a pivotal role in characterizing and understanding these protein-protein interactions that dictate protein quality control mechanisms. Here, we highlight the recent progress from mass spectrometry-based investigation of ER protein quality control in revealing the topological arrangement of the proteostasis network, stress response mechanisms that adjust the ER proteostasis capacity, and disease specific changes in proteostasis network engagement. We close by providing a brief outlook on underexplored areas of ER proteostasis where mass spectrometry is a tool uniquely primed to further expand our understanding of the regulation and coordination of protein quality control processes in diverse diseases.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2022

Advanced genomics identifies growth effectors for proteotoxic ER stress recovery in Arabidopsis thaliana

Abstract Adverse environmental and pathophysiological situations can overwhelm the biosynthetic capacity of the endoplasmic reticulum (ER), igniting a potentially lethal condition known as ER stress. ER stress hampers growth and triggers a conserved cytoprotective signaling cascade, the unfolded protein response (UPR) for ER homeostasis. As ER stress subsides, growth is resumed. Despite the pivotal role of the UPR in growth restoration, the underlying mechanisms for growth resumption are yet unknown. To discover these, we undertook a genomics approach in the model plant species Arabidopsis thaliana and mined the gene reprogramming roles of the UPR modulators, basic leucine zipper28 (bZIP28) and bZIP60, in ER stress resolution. Through a network modeling and experimental validation, we identified key genes downstream of the UPR bZIP-transcription factors (bZIP-TFs), and demonstrated their functional roles. Our analyses have set up a critical pipeline for functional gene discovery in ER stress resolution with broad applicability across multicellular eukaryotes.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2024

Powdery mildew effectors AVR A1 and BEC1016 target the ER J‐domain protein Hv ERdj3B required for immunity in barley

Abstract The barley powdery mildew fungus, Blumeria hordei (Bh), secretes hundreds of candidate secreted effector proteins (CSEPs) to facilitate pathogen infection and colonization. One of these, CSEP0008, is directly recognized by the barley nucleotide‐binding leucine‐rich‐repeat (NLR) receptor MLA1 and therefore is designated AVR A1 . Here, we show that AVR A1 and the sequence‐unrelated Bh effector BEC1016 (CSEP0491) suppress immunity in barley. We used yeast two‐hybrid next‐generation interaction screens (Y2H‐NGIS), followed by binary Y2H and in planta protein–protein interactions studies, and identified a common barley target of AVR A1 and BEC1016, the endoplasmic reticulum (ER)‐localized J‐domain protein Hv ERdj3B. Silencing of this ER quality control (ERQC) protein increased Bh penetration. Hv ERdj3B is ER luminal, and we showed using split GFP that AVR A1 and BEC1016 translocate into the ER signal peptide‐independently. Overexpression of the two effectors impeded trafficking of a vacuolar marker through the ER; silencing of Hv ERdj3B also exhibited this same cellular phenotype, coinciding with the effectors targeting this ERQC component. Together, these results suggest that the barley innate immunity, preventing Bh entry into epidermal cells, requires ERQC. Here, the J‐domain protein Hv ERdj3B appears to be essential and can be regulated by AVR A1 and BEC1016. Plant disease resistance often occurs upon direct or indirect recognition of pathogen effectors by host NLR receptors. Previous work has shown that AVR A1 is directly recognized in the cytosol by the immune receptor MLA1. We speculate that the AVR A1 J‐domain target being inside the ER, where it is inapproachable by NLRs, has forced the plant to evolve this challenging direct recognition.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2020

Materials Data on Er(NiGe)2 by Materials Project

Er(NiGe)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Er is bonded in a 8-coordinate geometry to eight equivalent Ni and eight equivalent Ge atoms. All Er–Ni bond lengths are 3.17 Å. All Er–Ge bond lengths are 3.12 Å. Ni is bonded in a 4-coordinate geometry to four equivalent Er and four equivalent Ge atoms. All Ni–Ge bond lengths are 2.35 Å. Ge is bonded in a 9-coordinate geometry to four equivalent Er, four equivalent Ni, and one Ge atom. The Ge–Ge bond length is 2.50 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Er(Fe2Ge)2 by Materials Project

ErFe4Ge2 crystallizes in the orthorhombic Pnnm space group. The structure is three-dimensional. Er is bonded in a 6-coordinate geometry to twelve Fe and six equivalent Ge atoms. There are a spread of Er–Fe bond distances ranging from 3.02–3.39 Å. There are two shorter (2.93 Å) and four longer (2.97 Å) Er–Ge bond lengths. There are two inequivalent Fe sites. In the first Fe site, Fe is bonded in a 3-coordinate geometry to three equivalent Er, four Fe, and three equivalent Ge atoms. There are a spread of Fe–Fe bond distances ranging from 2.43–2.61 Å. All Fe–Ge bond lengths are 2.41 Å. In the second Fe site, Fe is bonded in a 1-coordinate geometry to three equivalent Er, four Fe, and four equivalent Ge atoms. The Fe–Fe bond length is 2.66 Å. There are a spread of Fe–Ge bond distances ranging from 2.46–2.66 Å. Ge is bonded in a 10-coordinate geometry to three equivalent Er and seven Fe atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Er(FeB)2 by Materials Project

Er(FeB)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Er is bonded in a 8-coordinate geometry to eight equivalent Fe and eight equivalent B atoms. All Er–Fe bond lengths are 2.93 Å. All Er–B bond lengths are 2.93 Å. Fe is bonded in a 4-coordinate geometry to four equivalent Er and four equivalent B atoms. All Fe–B bond lengths are 2.00 Å. B is bonded in a 4-coordinate geometry to four equivalent Er and four equivalent Fe atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Er(Al2Fe)4 by Materials Project

ErFe4Al8 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Er is bonded in a 12-coordinate geometry to eight equivalent Fe and twelve Al atoms. All Er–Fe bond lengths are 3.31 Å. There are four shorter (2.95 Å) and eight longer (3.15 Å) Er–Al bond lengths. Fe is bonded in a 12-coordinate geometry to two equivalent Er, two equivalent Fe, and eight Al atoms. Both Fe–Fe bond lengths are 2.51 Å. There are four shorter (2.52 Å) and four longer (2.62 Å) Fe–Al bond lengths. There are two inequivalent Al sites. In the first Al site, Al is bonded in a 10-coordinate geometry to one Er, four equivalent Fe, and five Al atoms. There are a spread of Al–Al bond distances ranging from 2.72–2.80 Å. In the second Al site, Al is bonded in a 12-coordinate geometry to two equivalent Er, four equivalent Fe, and six Al atoms. Both Al–Al bond lengths are 2.70 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Er(SiIr)2 by Materials Project

Er(IrSi)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Er is bonded in a 8-coordinate geometry to eight equivalent Ir and eight equivalent Si atoms. All Er–Ir bond lengths are 3.21 Å. All Er–Si bond lengths are 3.12 Å. Ir is bonded to four equivalent Er and four equivalent Si atoms to form a mixture of distorted corner, edge, and face-sharing IrEr4Si4 tetrahedra. All Ir–Si bond lengths are 2.41 Å. Si is bonded in a 9-coordinate geometry to four equivalent Er, four equivalent Ir, and one Si atom. The Si–Si bond length is 2.40 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Er(GeRh)2 by Materials Project

Er(RhGe)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Er is bonded in a 8-coordinate geometry to eight equivalent Rh and eight equivalent Ge atoms. All Er–Rh bond lengths are 3.31 Å. All Er–Ge bond lengths are 3.18 Å. Rh is bonded to four equivalent Er and four equivalent Ge atoms to form a mixture of distorted edge, corner, and face-sharing RhEr4Ge4 tetrahedra. All Rh–Ge bond lengths are 2.46 Å. Ge is bonded in a 9-coordinate geometry to four equivalent Er, four equivalent Rh, and one Ge atom. The Ge–Ge bond length is 2.50 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Er(PPd)2 by Materials Project

Er(PdP)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Er is bonded in a 8-coordinate geometry to eight equivalent Pd and eight equivalent P atoms. All Er–Pd bond lengths are 3.21 Å. All Er–P bond lengths are 3.09 Å. Pd is bonded to four equivalent Er, four equivalent Pd, and four equivalent P atoms to form a mixture of distorted corner, edge, and face-sharing PdEr4P4Pd4 cuboctahedra. All Pd–Pd bond lengths are 2.89 Å. All Pd–P bond lengths are 2.47 Å. P is bonded in a 9-coordinate geometry to four equivalent Er, four equivalent Pd, and one P atom. The P–P bond length is 2.19 Å.

36 MATERIALS SCIENCE↗