Misfit layered compounds (MLCs) MX-TX2, where M, T = metal atoms and X = S, Se, or Te, and their nanotubes are of significant interest due to their rich chemistry and unique quasi-1D structure. In particular, LnX-TX2 (Ln = rare-earth atom) constitute a relatively large family of MLCs, from which nanotubes have been synthesized. The properties of MLCs can be tuned by the chemical and structural interplay between LnX and TX2 sublayers and alloying of each of the Ln, T, and X elements. In order to engineer them to gain desirable performance, a detailed understanding of their complex structure is indispensable. MLC nanotubes are a relative newcomer and offer new opportunities. In particular, like WS2 nanotubes before, the confinement of the free carriers in these quasi-1D nanostructures and their chiral nature offer intriguing physical behavior. High-resolution transmission electron microscopy in conjunction with a focused ion beam are engaged to study SmS-TaS2 nanotubes and their cross-sections at the atomic scale. The atomic resolution images distinctly reveal that Ta is in trigonal prismatic coordination with S atoms in a hexagonal structure. Furthermore, the position of the sulfur atoms in both the SmS and the TaS2 sublattices is revealed. X-ray photoelectron spectroscopy, electron energy loss spectroscopy, and X-ray absorption spectroscopy are carried out. These analyses conclude that charge transfer from the Sm to the Ta atoms leads to filling of the Ta 5d z 2 level, which is confirmed by density functional theory (DFT) calculations. Transport measurements show that the nanotubes are semimetallic with resistivities in the range of 10-4 Ω·cm at room temperature, and magnetic susceptibility measurements show a superconducting transition at 4 K.

Ames Laboratory U S Department of Energy Ames Iowa 50011 3020 United States

CEITEC Central European Institute of Technology Brno University of Technology Purkyňova 123 612 00 Brno Czech Republic

Department of Chemical Research Support Weizmann Institute Rehovot 7610001 Israel

Department of Molecular Chemistry and Materials Science Weizmann Institute of Science Rehovot 7610001 Israel

Department of Physics SUNY Buffalo State Buffalo New York 14222 United States

Deutsches Elektronen Synchrotron DESY Notkestr 85 22607 Hamburg Germany

Institute of Natural Sciences and Mathematics Ural Federal University 620083 Ekaterinburg Russian Federation

Institute of Physical Engineering Brno University of Technology Technická 2 616 69 Brno Czech Republic

Institute of Solid State Chemistry UB RAS 620990 Ekaterinburg Russian Federation

ProChem Inc 826 Roosevelt Road Rockford Illinois 61109 United States

Zobrazit více v PubMed

Makovicky E.; Hyde B. G.. Non-commensurate (misfit) layer structures. In Inorganic Chemistry; Structure and Bonding; Springer: Berlin, Heidelberg, 1981; Vol. 46, pp 101–170.

Williams T. B.; Hyde B. G. Electron microscopy of cylindrite and franckeite. Physics and Chemistry of Minerals 1988, 15 (6), 521–544. 10.1007/BF00311023. DOI

Wiegers G. A.; Meerschaut A.. Incommensurate Sandwiched Layered Compounds; Materials Science Forum; Meerschaut A., Ed.; Trans Tech Publications: Pfaffikon, Switzerland, 1992; Vol. 100–101, pp 223–272.

Wiegers G. A.; Meerschaut A. Structures of misfit layer compounds (MS)nTS2 (M= Sn, Pb, Bi, rare earth metals; T = Nb, Ta, Ti, V, Cr; 1.08 < n < 1.23). J. Alloys Compd. 1992, 178 (1), 351–368. 10.1016/0925-8388(92)90276-F. DOI

Oosawa Y.; Gotoh Y.; Akimoto J.; Tsunoda T.; Sohma M.; Onoda M. Three Types of Ternary Selenides with Layered Composite Crystal Structures Formed in the Pb-Nb-Se System. Jpn. J. Appl. Phys. 1992, 31 (Part 2, No. 8A), L1096–L1099. 10.1143/JJAP.31.L1096. DOI

Wiegers G. A. Misfit layer compounds: Structures and physical properties. Prog. Solid State Chem. 1996, 24 (1), 1–139. 10.1016/0079-6786(95)00007-0. DOI

Wiegers G. A.; Meetsma A.; Haange R. J.; de Boer J. L. Structure, electrical transport and magnetic properties of the misfit layer compound (SmS)1.19TaS2 “SmTaS3. Journal of the Less Common Metals 1991, 168 (2), 347–359. 10.1016/0022-5088(91)90317-W. DOI

Suzuki K.; Enoki T.; Bandow S. Electronic properties and valence state of Sm in (SmS)1.19TaS2. Phys. Rev. B 48 1993, 48 (15), 11077–11085. 10.1103/PhysRevB.48.11077. PubMed DOI

Lin Q.; Smeller M.; Heideman C. L.; Zschack P.; Koyano M.; Anderson M. D.; Kykyneshi R.; Keszler D. A.; Anderson I. M.; Johnson D. C. Rational Synthesis and Characterization of a New Family of Low Thermal Conductivity Misfit Layer Compounds [(PbSe)0.99]m(WSe2)n. Chem. Mater. 2010, 22 (3), 1002–1009. 10.1021/cm901952v. DOI

Merrill D. R.; Moore D. B.; Bauers S. R.; Falmbigl M.; Johnson D. C. Misfit Layer Compounds and Ferecrystals: Model Systems for Thermoelectric Nanocomposites. Materials 2015, 8 (4), 2000–2029. 10.3390/ma8042000. PubMed DOI PMC

Li Z.; Bauers S. R.; Poudel N.; Hamann D.; Wang X.; Choi D. S.; Esfarjani K.; Shi L.; Johnson D. C.; Cronin S. B. Cross-Plane Seebeck Coefficient Measurement of Misfit Layered Compounds (SnSe)n(TiSe2)n (n = 1,3,4,5). Nano Lett. 2017, 17 (3), 1978–1986. 10.1021/acs.nanolett.6b05402. PubMed DOI

Yin C.; Liu H.; Hu Q.; Tang J.; Pei Y.; Ang R. Texturization-Induced In-Plane High-Performance Thermoelectrics and Inapplicability of the Debye Model to Out-of-Plane Lattice Thermal Conductivity in Misfit-Layered Chalcogenides. ACS Appl. Mater. Interfaces 2019, 11 (51), 48079–48085. 10.1021/acsami.9b17964. PubMed DOI

Putri Y. E.; Wan C.; Wang Y.; Norimatsu W.; Kusunoki M.; Koumoto K. Effects of alkaline earth doping on the thermoelectric properties of misfit layer sulfides. Scr. Mater. 2012, 66 (11), 895–898. 10.1016/j.scriptamat.2012.02.010. DOI

Rouxel J.; Moeelo Y.; Lafond A.; DiSalvo F. J.; Meerschaut A.; Roesky R. Role of Vacancies in Misfit Layered Compounds: Case of the Gadolinium Chromium Sulfide Compound. Inorg. Chem. 1994, 33 (15), 3358–3363. 10.1021/ic00093a026. DOI

Lin Q.; Heideman C. L.; Nguyen N.; Zschack P.; Chiritescu C.; Cahill D. G.; Johnson D. C. Designed Synthesis of Families of Misfit-Layered Compounds. Eur. J. Inorg. Chem. 2008, 2008 (15), 2382–2385. 10.1002/ejic.200800158. DOI

Moore D. B.; Beekman M.; Disch S.; Johnson D. C. Telluride Misfit Layer Compounds: [(PbTe)1.17]m(TiTe2)n. Angew. Chem., Int. Ed. 2014, 53 (22), 5672–5675. 10.1002/anie.201401022. PubMed DOI

Panchakarla L. S.; Radovsky G.; Houben L.; Popovitz-Biro R.; Dunin-Borkowski R. E.; Tenne R. Nanotubes from Misfit Layered Compounds: A New Family of Materials with Low Dimensionality. J. Phys. Chem. Lett. 2014, 5 (21), 3724–3736. 10.1021/jz5016845. PubMed DOI

Bernaerts D.; Amelinckx S.; Van Tendeloo G.; Van Landuyt J. Microstructure and formation mechanism of cylindrical and conical scrolls of the misfit layer compounds PbNbnS2n+1. J. Cryst. Growth 1997, 172 (3), 433–439. 10.1016/S0022-0248(96)00747-6. DOI

Gómez-Herrero A.; Landa-Cánovas A. R.; Hansen S.; Otero-Díaz L. C. Electron microscopy study of tubular crystals (BiS)1+δ(NbS2)n. Micron 2000, 31 (5), 587–595. 10.1016/S0968-4328(99)00141-9. PubMed DOI

Qin F.; Shi W.; Ideue T.; Yoshida M.; Zak A.; Tenne R.; Kikitsu T.; Inoue D.; Hashizume D.; Iwasa Y. Superconductivity in a chiral nanotube. Nat. Commun. 2017, 8 (1), 14465.10.1038/ncomms14465. PubMed DOI PMC

Zhang Y. J.; Ideue T.; Onga M.; Qin F.; Suzuki R.; Zak A.; Tenne R.; Smet J. H.; Iwasa Y. Enhanced intrinsic photovoltaic effect in tungsten disulfide nanotubes. Nature 2019, 570 (7761), 349–353. 10.1038/s41586-019-1303-3. PubMed DOI

Hong S. Y.; Popovitz-Biro R.; Prior Y.; Tenne R. Synthesis of SnS2/SnS Fullerene-like Nanoparticles: A Superlattice with Polyhedral Shape. J. Am. Chem. Soc. 2003, 125 (34), 10470–10474. 10.1021/ja036057d. PubMed DOI

Ohno Y. Lamellar and filament-like crystals of misfit-layer compounds containing (Sm, Ta, S) and (Pb, Bi, Nb, S) elements. J. Solid State Chem. 2005, 178 (5), 1539–1550. 10.1016/j.jssc.2005.02.021. DOI

Serra M.; Arenal R.; Tenne R. An overview of the recent advances in inorganic nanotubes. Nanoscale 2019, 11 (17), 8073–8090. 10.1039/C9NR01880H. PubMed DOI

Hettler S.; Sreedhara M. B.; Serra M.; Sinha S. S.; Popovitz-Biro R.; Pinkas I.; Enyashin A. N.; Tenne R.; Arenal R. YS-TaS2 and YxLa1–xS-TaS2 (0 ≤ x ≤ 1) Nanotubes: A Family of Misfit Layered Compounds. ACS Nano 2020, 14 (5), 5445–5458. 10.1021/acsnano.9b09284. PubMed DOI PMC

Radovsky G.; Popovitz-Biro R.; Lorenz T.; Joswig J.-O.; Seifert G.; Houben L.; Dunin-Borkowski R. E.; Tenne R. Tubular structures from the LnS–TaS2 (Ln = La, Ce, Nd, Ho, Er) and LaSe–TaSe2 misfit layered compounds. J. Mater. Chem. C 2016, 4 (1), 89–98. 10.1039/C5TC02983J. DOI

Serra M.; Stolovas D.; Houben L.; Popovitz-Biro R.; Pinkas I.; Kampmann F.; Maultzsch J.; Joselevich E.; Tenne R. Synthesis and Characterization of Nanotubes from Misfit (LnS)1+yTaS2 (Ln = Pr, Sm, Gd, Yb) Compounds. Chem. Eur. J. 2018, 24 (44), 11354–11363. 10.1002/chem.201801877. PubMed DOI

Jayaraman A.; Bucher E.; Dernier P. D.; Longinotti L. D. Temperature-Induced Explosive First-Order Electronic Phase Transition in Gd-Doped SmS. Phys. Rev. Lett. 1973, 31 (11), 700–703. 10.1103/PhysRevLett.31.700. DOI

Hall J.; Ehlen N.; Berges J.; van Loon E.; van Efferen C.; Murray C.; Rösner M.; Li J.; Senkovskiy B. V.; Hell M.; Rolf M.; Heider T.; Asensio M. C.; Avila J.; Plucinski L.; Wehling T.; Grüneis A.; Michely T. Environmental Control of Charge Density Wave Order in Monolayer 2H-TaS2. ACS Nano 2019, 13 (9), 10210–10220. 10.1021/acsnano.9b03419. PubMed DOI

Rogers E.; Smet P. F.; Dorenbos P.; Poelman D.; van der Kolk E. The thermally induced metal–semiconducting phase transition of samarium monosulfide (SmS) thin films. J. Phys.: Condens. Matter 2010, 22 (1), 015005.10.1088/0953-8984/22/1/015005. PubMed DOI

Sousanis A.; Smet P. F.; Poelman D. Samarium Monosulfide (SmS): Reviewing Properties and Applications. Materials 2017, 10 (8), 953.10.3390/ma10080953. PubMed DOI PMC

Jayaraman A.; Narayanamurti V.; Bucher E.; Maines R. G. Continuous and Discontinuous Semiconductor-Metal Transition in Samarium Monochalcogenides Under Pressure. Phys. Rev. Lett. 1970, 25 (20), 1430–1433. 10.1103/PhysRevLett.25.1430. DOI

Barla A.; Sanchez J. P.; Haga Y.; Lapertot G.; Doyle B. P.; Leupold O.; Rüffer R.; Abd-Elmeguid M. M.; Lengsdorf R.; Flouquet J. Pressure-Induced Magnetic Order in Golden SmS. Phys. Rev. Lett. 2004, 92 (6), 066401.10.1103/PhysRevLett.92.066401. PubMed DOI

Pan J.; Guo C.; Song C.; Lai X.; Li H.; Zhao W.; Zhang H.; Mu G.; Bu K.; Lin T.; Xie X.; Chen M.; Huang F. Enhanced Superconductivity in Restacked TaS2 Nanosheets. J. Am. Chem. Soc. 2017, 139 (13), 4623–4626. 10.1021/jacs.7b00216. PubMed DOI

Meetsma A.; Wiegers G. A.; Haange R. J.; de Boer J. L. Structure of 2H-TaS2. Acta Crystallogr. 1990, 46 (9), 1598–1599. 10.1107/S0108270190000014. DOI

Winiarz S.; Klimczuk T.; Cava R. J.; Czajka R. Nanostructure characterization of (SmS)1.19TaS2 by means of STM/STS. J. Cryst. Growth 2006, 297 (1), 7–9. 10.1016/j.jcrysgro.2006.09.030. DOI

Sreedhara M. B.; Hettler S.; Kaplan-Ashiri I.; Rechav K.; Feldman Y.; Enyashin A.; Houben L.; Arenal R.; Tenne R. Asymmetric misfit nanotubes: Chemical affinity outwits the entropy at high-temperature solid-state reactions. Proc. Natl. Acad. Sci. U.S.A. 2021, 118 (35), e2109945118.10.1073/pnas.2109945118. PubMed DOI PMC

Dolotko O.; Hlova I. Z.; Pathak A. K.; Mudryk Y.; Pecharsky V. K.; Singh P.; Johnson D. D.; Boote B. W.; Li J.; Smith E. A.; Carnahan S. L.; Rossini A. J.; Zhou L.; Eastman E. M.; Balema V. P. Unprecedented generation of 3D heterostructures by mechanochemical disassembly and re-ordering of incommensurate metal chalcogenides. Nat. Commun. 2020, 11 (1), 3005.10.1038/s41467-020-16672-0. PubMed DOI PMC

Fang C. M.; Wiegers G. A.; Haas C. Photoelectron spectra of the late rare-earth misfit layer compounds (LnS)1+xTS2 (Ln = Tb, Dy, Ho; T = Nb, Ta). Physica B 1997, 233 (2), 134–138. 10.1016/S0921-4526(97)89578-6. DOI

Cario L.; Johrendt D.; Lafond A.; Felser C.; Meerschaut A.; Rouxel J. Stability and charge transfer in the misfit compound (LaS)(SrS)0.2CrS2: Ab initio band-structure calculations. Phys. Rev. B 1997, 55 (15), 9409–9414. 10.1103/PhysRevB.55.9409. DOI

Serra M.; Lajaunie L.; Sreedhara M. B.; Miroshnikov Y.; Pinkas I.; Calvino J. J.; Enyashin A. N.; Tenne R. Quaternary LnxLa(1-x)S-TaS2 nanotubes (Ln = Pr, Sm, Ho, and Yb) as a vehicle for improving the yield of misfit nanotubes. Appl. Mater. Today 2020, 19, 100581.10.1016/j.apmt.2020.100581. DOI

Lorenz T.; Baburin I. A.; Joswig J.-O.; Seifert G. Charge Transfer Variability in Misfit Layer Compounds: Comparison of SnS-SnS2 and LaS-TaS2. Isr. J. Chem. 2017, 57 (6), 553–559. 10.1002/ijch.201600148. DOI

Ordejón P.; Artacho E.; Soler J. M. Self-consistent order-N density-functional calculations for very large systems. Phys. Rev. B 1996, 53 (16), R10441–R10444. 10.1103/PhysRevB.53.R10441. PubMed DOI

García A.; Papior N.; Akhtar A.; Artacho E.; Blum V.; Bosoni E.; Brandimarte P.; Brandbyge M.; Cerdá J. I.; Corsetti F.; Cuadrado R.; Dikan V.; Ferrer J.; Gale J.; García-Fernández P.; García-Suárez V. M.; García S.; Huhs G.; Illera S.; Korytár R.; Koval P.; Lebedeva I.; Lin L.; López-Tarifa P.; Mayo S. G.; Mohr S.; Ordejón P.; Postnikov A.; Pouillon Y.; Pruneda M.; Robles R.; Sánchez-Portal D.; Soler J. M.; Ullah R.; Yu V. W.-z.; Junquera J. Siesta: Recent developments and applications. J. Chem. Phys. 2020, 152 (20), 204108.10.1063/5.0005077. PubMed DOI

Moreno J.; Soler J. M. Optimal meshes for integrals in real- and reciprocal-space unit cells. Phys. Rev. B 1992, 45 (24), 13891–13898. 10.1103/PhysRevB.45.13891. PubMed DOI

Csonka G. I.; Perdew J. P.; Ruzsinszky A.; Philipsen P. H. T.; Lebègue S.; Paier J.; Vydrov O. A.; Ángyán J. G. Assessing the performance of recent density functionals for bulk solids. Phys. Rev. B 2009, 79 (15), 155107.10.1103/PhysRevB.79.155107. DOI

Cohen A. J.; Mori-Sánchez P.; Yang W. Challenges for Density Functional Theory. Chem. Rev. 2012, 112 (1), 289–320. 10.1021/cr200107z. PubMed DOI

Li W.; Walther C. F. J.; Kuc A.; Heine T. Density Functional Theory and Beyond for Band-Gap Screening: Performance for Transition-Metal Oxides and Dichalcogenides. J. Chem. Theory Comput. 2013, 9 (7), 2950–2958. 10.1021/ct400235w. PubMed DOI

Dudarev S. L.; Botton G. A.; Savrasov S. Y.; Humphreys C. J.; Sutton A. P. Electron-energy-loss spectra and the structural stability of nickel oxide: An LSDA+U study. Phys. Rev. B 1998, 57 (3), 1505–1509. 10.1103/PhysRevB.57.1505. DOI

Sinha S. S.; Sreedhara M. B.; Tenne R. Why do nanocrystals of 2D materials form nanotubes and why is that important?. Nano Today 2021, 37, 101060.10.1016/j.nantod.2020.101060. DOI

Stolovas D.; Popovitz-Biro R.; Sinha S. S.; Bitton O.; Shahar D.; Tenne R.; Joselevich E. Electrical Properties of LaS-TaS2 Misfit Layered Compound Nanotubes. Isr. J. Chem. 2021, 10.1002/ijch.202100072. DOI

Rouxel J.; Meerschaut A.; Wiegers G. A. Chalcogenide misfit layer compounds. J. Alloys Compd. 1995, 229 (1), 144–157. 10.1016/0925-8388(95)01680-5. DOI

Slough C. G.; McNairy W. W.; Coleman R. V.; Drake B.; Hansma P. K. Charge-density waves studied with the use of a scanning tunneling microscope. Phys. Rev. B 1986, 34 (2), 994–1005. 10.1103/PhysRevB.34.994. PubMed DOI

Chamlagain B.; Cui Q.; Paudel S.; Cheng M. M.-C.; Chen P.-Y.; Zhou Z. Thermally oxidized 2D TaS2 as a high- κ gate dielectric for MoS2 field-effect transistors. 2D Materials 2017, 4 (3), 031002.10.1088/2053-1583/aa780e. DOI

Mori Y.; Tanemura S. Chemical analysis of semiconducting and metallic SmS thin films by X-ray photoelectron spectroscopy. Appl. Surf. Sci. 2007, 253 (8), 3856–3859. 10.1016/j.apsusc.2006.08.011. DOI

Doron-Mor I.; Hatzor A.; Vaskevich A.; van der Boom-Moav T.; Shanzer A.; Rubinstein I.; Cohen H. Controlled surface charging as a depth-profiling probe for mesoscopic layers. Nature 2000, 406 (6794), 382–385. 10.1038/35019025. PubMed DOI

Shabtai K.; Rubinstein I.; Cohen S. R.; Cohen H. High-Resolution Lateral Differentiation Using a Macroscopic Probe: XPS of Organic Monolayers on Composite Au–SiO2 Surfaces. J. Am. Chem. Soc. 2000, 122 (20), 4959–4962. 10.1021/ja993710h. DOI

Cohen H. Chemically resolved electrical measurements using x-ray photoelectron spectroscopy. Appl. Phys. Lett. 2004, 85 (7), 1271–1273. 10.1063/1.1782261. DOI

Filip-Granit N.; Goldberg E.; Samish I.; Ashur I.; van der Boom M. E.; Cohen H.; Scherz A. Submolecular Gates Self-Assemble for Hot-Electron Transfer in Proteins. J. Phys. Chem. B 2017, 121 (29), 6981–6988. 10.1021/acs.jpcb.7b00432. PubMed DOI

Lazar S.; Botton G. A.; Wu M. Y.; Tichelaar F. D.; Zandbergen H. W. Materials science applications of HREELS in near edge structure analysis and low-energy loss spectroscopy. Ultramicroscopy 2003, 96 (3), 535–546. 10.1016/S0304-3991(03)00114-1. PubMed DOI

García de Abajo F. J. Optical excitations in electron microscopy. Rev. Mod. Phys. 2010, 82 (1), 209–275. 10.1103/RevModPhys.82.209. DOI

Stöger-Pollach M. Optical properties and bandgaps from low loss EELS: Pitfalls and solutions. Micron 2008, 39 (8), 1092–1110. 10.1016/j.micron.2008.01.023. PubMed DOI

Deen P. P.; Braithwaite D.; Kernavanois N.; Paolasini L.; Raymond S.; Barla A.; Lapertot G.; Sanchez J. P. Structural and electronic transitions in the low-temperature, high-pressure phase of SmS. Phys. Rev. B 2005, 71 (24), 245118.10.1103/PhysRevB.71.245118. DOI

Menushenkov A. P.; Chernikov R. V.; Sidorov V. V.; Klementiev K. V.; Alekseev P. A.; Rybina A. V. Relationship between the local electronic and local crystal structures of intermediate-valence Sm1–xYxS. Jetp Lett. 2006, 84 (3), 119–123. 10.1134/S0021364006150045. DOI

Fieser M. E.; Ferrier M. G.; Su J.; Batista E.; Cary S. K.; Engle J. W.; Evans W. J.; Lezama Pacheco J. S.; Kozimor S. A.; Olson A. C.; Ryan A. J.; Stein B. W.; Wagner G. L.; Woen D. H.; Vitova T.; Yang P. Evaluating the electronic structure of formal LnII ions in LnII(C5H4SiMe3)3– using XANES spectroscopy and DFT calculations. Chem. Sci. 2017, 8 (9), 6076–6091. 10.1039/C7SC00825B. PubMed DOI PMC

Kim T. K.; Babenko V. P.; Novgorodov B. N.; Kochubey D. I.; Shaikhutdinov S. K. Destruction of the charge density wave structure in 1T-TaS2 under pyridine intercalation. Nucl. Instruments Methods Phys. Res. Sect. A Accel. Spectrometers, Detect. Assoc. Equip. 1998, 405 (2), 348–350. 10.1016/S0168-9002(97)00185-X. DOI

Kochubey D. I.; Kim T. K.; Babenko V. P.; Shaikhutdinov S. K. Charge density waves in 1T-TaS2: an EXAFS study. Phys. B Condens. Matter 1998, 252 (1), 15–20. 10.1016/S0921-4526(98)00050-7. DOI

Tsuchiya T.; Imai H.; Miyoshi S.; Glans P.-A.; Guo J.; Yamaguchi S. X-Ray absorption, photoemission spectroscopy, and Raman scattering analysis of amorphous tantalum oxide with a large extent of oxygen nonstoichiometry. Phys. Chem. Chem. Phys. 2011, 13 (38), 17013–17018. 10.1039/c1cp21310e. PubMed DOI

Cartier C.; Hammouda T.; Boyet M.; Mathon O.; Testemale D.; Moine B. N. Evidence for Nb2+ and Ta3+ in silicate melts under highly reducing conditions: A XANES study. Am. Mineral. 2015, 100 (10), 2152–2158. 10.2138/am-2015-5330. DOI

Acrivos J. V.; Parkin S. S. P.; Code J.; Reynolds J.; Hathaway K.; Kurasaki H.; Marseglia E. A. Conduction band symmetry in Ta chalcogenides from Ta L edge X-ray absorption spectroscopy (XAS). J. Phys. C: Solid State Phys. 1981, 14 (11), L349–L357. 10.1088/0022-3719/14/11/014. DOI

Wachter P.Intermediate valence and heavy fermions. In Handbook on the Physics and Chemistry of Rare Earths; Elsevier: 1994; Vol. 19, Chapter 132, pp 177–382.

Kimura S.-i.; Mizuno T.; Matsubayashi K.; Imura K.; Suzuki H. S.; Sato N. K. Infrared study on the electronic structure of SmS in the black phase. Physica B 2008, 403 (5), 805–807. 10.1016/j.physb.2007.10.095. DOI

Svane A.; Santi G.; Szotek Z.; Temmerman W. M.; Strange P.; Horne M.; Vaitheeswaran G.; Kanchana V.; Petit L.; Winter H. Electronic structure of Sm and Eu chalcogenides. phys. stat. sol. (b) 2004, 241 (14), 3185–3192. 10.1002/pssb.200405226. DOI

Yan-Bin Q.; Yan-Ling L.; Guo-Hua Z.; Zhi Z.; Xiao-Ying Q. Anisotropic properties of TaS2. Chinese Phys. 2007, 16 (12), 3809–3814. 10.1088/1009-1963/16/12/042. DOI

Winterlik J.; Fecher G. H.; Felser C.; Jourdan M.; Grube K.; Hardy F.; von Löhneysen H.; Holman K. L.; Cava R. J. Ni-based superconductor: Heusler compound ZrNi2\Ga. Phys. Rev. B 2008, 78 (18), 184506.10.1103/PhysRevB.78.184506. DOI

Liu H.; Huangfu S.; Zhang X.; Lin H.; Schilling A. Superconductivity and charge density wave formation in lithium-intercalated 2H-TaS2. Phys. Rev. B 2021, 104 (6), 064511.10.1103/PhysRevB.104.064511. DOI

Reefman D.; Baak J.; Brom H. B.; Wiegers G. A. Superconductivity in misfit layer compounds (MS)nTS2. Solid State Commun. 1990, 75 (1), 47–51. 10.1016/0038-1098(90)90155-5. DOI

Ashcroft N. W.; Mermin N. D.. Solid State Physics; Saunders College Publishers, Cornell University, 1976.

Tidman J. P.; Singh O.; Curzon A. E.; Frindt R. F. The phase transition in 2H-TaS2 at 75 K. Philos. Mag. 1974, 30 (5), 1191–1194. 10.1080/14786437408207274. DOI

Stevens-Kalceff M. A.; Liu Z.; Riesen H. Cathodoluminescence Microanalysis of Irradiated Microcrystalline and Nanocrystalline Samarium Doped BaFCl. Microsc. Microanal. 2012, 18 (6), 1229–1238. 10.1017/S1431927612001559. PubMed DOI