Biomaterial Database

Spin tuning of electron-doped metal-phthalocyanine layers. 2014

Sebastian Stepanow, and Alberto Lodi Rizzini, and Cornelius Krull, and Jerald Kavich, and Julio C Cezar, and Flora Yakhou-Harris, and Polina M Sheverdyaeva, and Paolo Moras, and Carlo Carbone, and Gustavo Ceballos, and Aitor Mugarza, and Pietro Gambardella

Department of Materials, ETH Zürich , Hönggerbergring 64, 8093 Zürich, Switzerland.

The spin state of organic-based magnets at interfaces is to a great extent determined by the organic environment and the nature of the spin-carrying metal center, which is further subject to modifications by the adsorbate-substrate coupling. Direct chemical doping offers an additional route for tailoring the electronic and magnetic characteristics of molecular magnets. Here we present a systematic investigation of the effects of alkali metal doping on the charge state and crystal field of 3d metal ions in Cu, Ni, Fe, and Mn phthalocyanine (Pc) monolayers adsorbed on Ag. Combined X-ray absorption spectroscopy and ligand field multiplet calculations show that Cu(II), Ni(II), and Fe(II) ions reduce to Cu(I), Ni(I), and Fe(I) upon alkali metal adsorption, whereas Mn maintains its formal oxidation state. The strength of the crystal field at the Ni, Fe, and Mn sites is strongly reduced upon doping. The combined effect of these changes is that the magnetic moment of high- and low-spin ions such as Cu and Ni can be entirely turned off or on, respectively, whereas the magnetic configuration of MnPc can be changed from intermediate (3/2) to high (5/2) spin. In the case of FePc a 10-fold increase of the orbital magnetic moment accompanies charge transfer and a transition to a high-spin state.

UI	MeSH Term	Description	Entries
D007211	Indoles	Benzopyrroles with the nitrogen at the number one carbon adjacent to the benzyl portion, in contrast to ISOINDOLES which have the nitrogen away from the six-membered ring.
D008672	Metals, Alkali	Metals that constitute group 1(formerly group IA) of the periodic table. They are the most strongly electropositive of the metals. Note that HYDROGEN is not considered an alkali metal even though it falls under the group 1 heading in the periodic table.	Alkali Metal,Alkali Metals,Group 1 Element,Group 1 Elements,1 Element, Group,Element, Group 1,Elements, Group 1,Metal, Alkali
D009942	Organometallic Compounds	A class of compounds of the type R-M, where a C atom is joined directly to any other element except H, C, N, O, F, Cl, Br, I, or At. (Grant & Hackh's Chemical Dictionary, 5th ed)	Metallo-Organic Compound,Metallo-Organic Compounds,Metalloorganic Compound,Organometallic Compound,Metalloorganic Compounds,Compound, Metallo-Organic,Compound, Metalloorganic,Compound, Organometallic,Compounds, Metallo-Organic,Compounds, Metalloorganic,Compounds, Organometallic,Metallo Organic Compound,Metallo Organic Compounds
D002942	Circular Dichroism	A change from planar to elliptic polarization when an initially plane-polarized light wave traverses an optically active medium. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Circular Dichroism, Vibrational,Dichroism, Circular,Vibrational Circular Dichroism
D004583	Electrons	Stable elementary particles having the smallest known negative charge, present in all elements; also called negatrons. Positively charged electrons are called positrons. The numbers, energies and arrangement of electrons around atomic nuclei determine the chemical identities of elements. Beams of electrons are called CATHODE RAYS.	Fast Electrons,Negatrons,Positrons,Electron,Electron, Fast,Electrons, Fast,Fast Electron,Negatron,Positron
D016252	Microscopy, Scanning Tunneling	A type of scanning probe microscopy in which a very sharp conducting needle is swept just a few angstroms above the surface of a sample. The tiny tunneling current that flows between the sample and the needle tip is measured, and from this are produced three-dimensional topographs. Due to the poor electron conductivity of most biological samples, thin metal coatings are deposited on the sample.	Scanning Tunneling Microscopy,Scanning Tunnelling Microscopy,Microscopies, Scanning Tunneling,Microscopies, Scanning Tunnelling,Microscopy, Scanning Tunnelling,Scanning Tunneling Microscopies,Scanning Tunnelling Microscopies,Tunneling Microscopies, Scanning,Tunneling Microscopy, Scanning,Tunnelling Microscopies, Scanning,Tunnelling Microscopy, Scanning
D054833	Isoindoles	Benzopyrroles with the nitrogen at the number two carbon, in contrast to INDOLES which have the nitrogen adjacent to the six-membered ring.	Isoindole
D056928	X-Ray Absorption Spectroscopy	Analysis of the energy absorbed across a spectrum of x-ray energies/wavelengths to determine the chemical structure and electronic states of the absorbing medium.	Near Edge X-Ray Absorption Fine Structure Spectroscopy,NEXAFS Spectroscopy,Near-Edge X-Ray Absorption Fine Structure Spectroscopy,X-Ray Absorption Near Edge Structure Spectroscopy,X-Ray Absorption Near-Edge Structure Spectroscopy,XANES Spectroscopy,Absorption Spectroscopy, X-Ray,Near Edge X Ray Absorption Fine Structure Spectroscopy,Spectroscopy, NEXAFS,Spectroscopy, X-Ray Absorption,Spectroscopy, XANES,X Ray Absorption Near Edge Structure Spectroscopy,X Ray Absorption Spectroscopy
D019216	Metals, Heavy	Metals with high specific gravity, typically larger than 5. They have complex spectra, form colored salts and double salts, have a low electrode potential, are mainly amphoteric, yield weak bases and weak acids, and are oxidizing or reducing agents (From Grant & Hackh's Chemical Dictionary, 5th ed)	Heavy Metal,Heavy Metals,Metal, Heavy