@article{canevet_fak_kremer_chun_enderle_gordon_bettis_whangbo_taylor_adroja_2015, title={Spin excitations in the two-dimensional strongly coupled dimer system malachite}, volume={91}, ISSN={["1550-235X"]}, DOI={10.1103/physrevb.91.060402}, abstractNote={The mineral malachite, Cu2(OD)2CO3, has a quantum spin-liquid ground state and no long-range magnetic order down to at least T=0.4 K. Inelastic neutron scattering measurements show that the excitation spectrum consists of dispersive gapped singlet-triplet excitations, characteristic of spin-1/2 dimer-forming Heisenberg antiferromagnets. We identify a new two-dimensional dimerized coupling scheme with strong interdimer coupling J'/J1~0.3 that places malachite between strongly coupled alternating chains, square lattice antiferromagnets, and infinite-legged ladders. The geometry of the interaction scheme resembles the staggered dimer lattice, which may allow unconventional quantum criticality.}, number={6}, journal={PHYSICAL REVIEW B}, author={Canevet, E. and Fak, B. and Kremer, R. K. and Chun, J. H. and Enderle, M. and Gordon, E. E. and Bettis, J. L. and Whangbo, M. -H. and Taylor, J. W. and Adroja, D. T.}, year={2015}, month={Feb} }
 @article{whangbo_gordon_bettis_bussmann-holder_koehler_2015, title={Tolerance Factor and Cation-Anion Orbital Interactions Differentiating the Polar and Antiferrodistortive Structures of Perovskite Oxides ABO(3)}, volume={641}, ISSN={["1521-3749"]}, DOI={10.1002/zaac.201500058}, abstractNote={Abstract}, number={6}, journal={ZEITSCHRIFT FUR ANORGANISCHE UND ALLGEMEINE CHEMIE}, author={Whangbo, Myung-Hwan and Gordon, Elijah E. and Bettis, Jerry L., Jr. and Bussmann-Holder, Annette and Koehler, Juergen}, year={2015}, month={May}, pages={1043–1052} }
 @article{hu_johnsson_law_bettis_whangbo_kremer_2014, title={Crystal Structure and Magnetic Properties of FeSeO3F-Alternating Antiferromagnetic S=5/2 chains}, volume={53}, ISSN={["1520-510X"]}, DOI={10.1021/ic5003995}, abstractNote={The new oxofluoride FeSeO3F, which is isostructural with FeTeO3F and GaTeO3F, was prepared by hydrothermal synthesis, and its structure was determined by X-ray diffraction. The magnetic properties of FeSeO3F were characterized by magnetic susceptibility and specific heat measurements, by evaluating its spin exchanges on the basis of density functional theory (DFT) calculations, and by performing a quantum Monte Carlo simulation of the magnetic susceptibility. FeSeO3F crystallizes in the monoclinic space group P21/n and has one unique Se(4+) ion and one unique Fe(3+) ion. The building blocks of FeSeO3F are [SeO3] trigonal pyramids and cis-[FeO4F2] distorted octahedra. The cis-[FeO4F2] octahedra are condensed by sharing the O-O and F-F edges alternatingly to form [FeO3F]∞ chains, which are interconnected via the [SeO3] pyramids by corner-sharing. The magnetic susceptibility of FeSeO3F is characterized by a broad maximum at 75(2) K and a long-range antiferromagnetic order below ∼45 K. The latter is observed by magnetic susceptibility and specific heat measurements. DFT calculations show that the Fe-F-Fe spin exchange is stronger than the Fe-O-Fe exchange, so each [FeO3F]∞ chain is a Heisenberg antiferromagnetic chain with alternating antiferromagnetic spin exchanges. The temperature dependence of the magnetic susceptibility is well-reproduced by a quantum-Monte Carlo simulation.}, number={8}, journal={INORGANIC CHEMISTRY}, author={Hu, Shichao and Johnsson, Mats and Law, Joseph M. and Bettis, Jerry L., Jr. and Whangbo, Myung-Hwan and Kremer, Reinhard K.}, year={2014}, month={Apr}, pages={4250–4256} }
 @article{mccabe_stock_bettis_whangbo_evans_2014, title={Magnetism of the Fe2+ and Ce3+ sublattices in Ce2O2FeSe2: A combined neutron powder diffraction, inelastic neutron scattering, and density functional study}, volume={90}, ISSN={["2469-9969"]}, DOI={10.1103/physrevb.90.235115}, abstractNote={The discovery of superconductivity in the 122 iron selenide materials above 30 K necessitates an understanding of the underlying magnetic interactions. We present a combined experimental and theoretical investigation of magnetic and semiconducting Ce 2 O 2 FeSe 2 composed of chains of edge-linked iron selenide tetrahedra. The combined neutron diffraction and inelastic scattering study and density functional calculations confirm the ferromagnetic nature of nearest-neighbor Fe-Se-Fe interactions in the ZrCuSiAs-related iron oxyselenide Ce 2 O 2 FeSe 2 . Inelastic measurements provide an estimate of the strength of nearest-neighbor Fe-Fe and Fe-Ce interactions. These are consistent with density functional theory calculations, which reveal that correlations in the Fe-Se sheets of Ce 2 O 2 FeSe 2 are weak. The Fe on-site repulsion U Fe is comparable to that reported for oxyarsenides and K 1−x Fe 2−y Se 2 , which are parents to iron-based superconductors.}, number={23}, journal={PHYSICAL REVIEW B}, author={McCabe, E. E. and Stock, C. and Bettis, J. L., Jr. and Whangbo, M. -H. and Evans, J. S. O.}, year={2014}, month={Dec} }
 @article{bao_ma_chen_xu_enriquez_chen_zhang_bettis_whangbo_dong_et al._2014, title={Ultrafast atomic layer-by-layer oxygen vacancy-exchange diffusion in double-perovskite LnBaCo(2)O(5.5+delta) thin films}, volume={4}, journal={Scientific Reports}, author={Bao, S. Y. and Ma, C. R. and Chen, G. and Xu, X. and Enriquez, E. and Chen, C. L. and Zhang, Y. M. and Bettis, J. L. and Whangbo, M. H. and Dong, C. and et al.}, year={2014} }
 @article{jin_kim_jo_bettis_koo_whangbo_hwang_2013, title={A Crucial Role of Bond Covalency Competition in Determining the Bandgap and Photocatalytic Performance of Silver Oxosalts}, volume={117}, ISSN={["1932-7455"]}, DOI={10.1021/jp4101784}, abstractNote={The optical bandgaps, the surface charges, and the photocatalytic activities of the silver oxosalts Ag3AsO4, Ag2CO3, Ag3PO4, Ag2SO4, and Ag2SeO4 are systematically investigated with several experimental techniques and first principles density functional theory calculations. The trends in the optical bandgaps and the surface charges of these silver oxosalts, Agx(XOy)z, are analyzed by considering how the X–O bond covalency affects the charge on the terminal oxygen atoms and the Ag–O bond covalency. The optical bandgaps of Agx(XOy)z are well-described by the bond-covalency competition in the Ag–O–X linkages because an increase in the overlap between the O 2s/2p and X ns/np orbitals decreases the overlap between the Ag 4d and O 2s/2p orbitals. The optical bandgap increases linearly with increasing the Z/r ratio of the atom X, a simple measure of the X–O bond covalency. In the photodegradation of charged molecules, the surface charge of Agx(XOy)z plays a prominent role and decreases with increasing the Z/r ra...}, number={50}, journal={JOURNAL OF PHYSICAL CHEMISTRY C}, author={Jin, Xiaoyan and Kim, In Young and Jo, Yun Kyung and Bettis, Jerry L., Jr. and Koo, Hyun-Joo and Whangbo, Myung-Hwan and Hwang, Seong-Ju}, year={2013}, month={Dec}, pages={26509–26516} }
 @article{nenert_bettis_kremer_ben yahia_ritter_gaudin_isnard_whangbo_2013, title={Magnetic Properties of the RbMnPO4 Zeolite-ABW-Type Material: A Frustrated Zigzag Spin Chain}, volume={52}, ISSN={["1520-510X"]}, DOI={10.1021/ic401408f}, abstractNote={The crystal structure and magnetic properties of the RbMnPO4 zeolite-ABW-type material have been studied by temperature-dependent neutron powder diffraction, low-temperature magnetometry, and heat capacity measurements. RbMnPO4 represents a rare example of a weak ferromagnetic polar material, containing Mn(2+) ions with TN = 4.7 K. The neutron powder diffraction pattern recorded at T = 10 K shows that the compound crystallizes in the chiral and polar monoclinic space group P2(1) (No. 4) with the unit cell parameters: a = 8.94635(9), b = 5.43415(5), and c = 9.10250(8) Å and β = 90.4209(6)°. A close inspection of the crystal structure of RbMnPO4 shows that this material presents two different types of zigzag chains running along the b axis. This is a unique feature among the zeolite-ABW-type materials exhibiting the P2(1) symmetry. At low temperature, RbMnPO4 exhibits a canted antiferromagnetic structure characterized by the propagation vector k1 = 0, resulting in the magnetic symmetry P2(1)'. The magnetic moments lie mostly along the b axis with the ferromagnetic component being in the ac plane. Due to the geometrical frustration present in this system, an intermediate phase appears within the temperature range 4.7-5.1 K characterized by the propagation vector k2 = (kx, 0, kz) with kx/kz ≈ 2. This ratio is reminiscent of the multiferroic phase of the orthorhombic RMnO3 phases (R = rare earth), suggesting that RbMnPO4 could present some multiferroic properties at low temperature. Our density functional calculations confirm the presence of magnetic frustration, which explains this intermediate incommensurate phase. Taking into account the strongest magnetic interactions, we are able to reproduce the magnetic structure observed experimentally at low temperature.}, number={16}, journal={INORGANIC CHEMISTRY}, author={Nenert, Gwilherm and Bettis, Jerry, Jr. and Kremer, Reinhard and Ben Yahia, Hamdi and Ritter, Clemens and Gaudin, Etienne and Isnard, Olivier and Whangbo, Myung-Hwan}, year={2013}, month={Aug}, pages={9627–9635} }
 @article{guguchia_caslin_kremer_keller_shengelaya_maisuradze_bettis_kohler_bussmann-holder_whangbo_2013, title={Nonlinear pressure dependence of T-N in almost multiferroic EuTiO3}, volume={25}, number={37}, journal={Journal of Physics. Condensed Matter}, author={Guguchia, Z. and Caslin, K. and Kremer, R. K. and Keller, H. and Shengelaya, A. and Maisuradze, A. and Bettis, J. L. and Kohler, J. and Bussmann-Holder, A. and Whangbo, M. H.}, year={2013} }
 @article{bettis_xiang_whangbo_2012, title={Origin of the Room-Temperature Ferromagnetism in Sr3YCo4O10+delta (0.5 < delta < 1.0): Formation of Ferromagnetic Spin Bags in the Oxygen-Rich Perovskite Layers}, volume={24}, ISSN={["0897-4756"]}, DOI={10.1021/cm302007q}, abstractNote={ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTOrigin of the Room-Temperature Ferromagnetism in Sr3YCo4O10+δ (0.5 < δ < 1.0): Formation of Ferromagnetic Spin Bags in the Oxygen-Rich Perovskite LayersJerry L. Bettis, Jr.†, Hongjun Xiang‡, and Myung-Hwan Whangbo†*View Author Information† Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States ‡ Key Laboratory of Computational Physical Sciences (Ministry of Education) and Department of Physics, Fudan University, Shanghai 200433, P. R. China*E-mail: [email protected]Cite this: Chem. Mater. 2012, 24, 16, 3117–3119Publication Date (Web):August 9, 2012Publication History Received27 June 2012Revised9 August 2012Published online10 August 2012Published inissue 28 August 2012https://doi.org/10.1021/cm302007qCopyright © 2012 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views673Altmetric-Citations9LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit Read OnlinePDF (1 MB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting Information SUBJECTS:Chemical calculations,Ions,Layers,Magnetic properties,Quantum mechanics Get e-Alerts}, number={16}, journal={CHEMISTRY OF MATERIALS}, author={Bettis, Jerry L., Jr. and Xiang, Hongjun and Whangbo, Myung-Hwan}, year={2012}, month={Aug}, pages={3117–3119} }