Muoniated radical states in the organic semiconductor phthalocyanine

Phthalocyanine samples of ZnPc, H2Pc and CuPc were investigated by the muon spin rotation amp; 956;SR technique. In ZnPc and H2Pc, three muoniated radical states of paramagnetic origin were identified, two of which having hyperfine interactions in the range 110 150 MHz and correspondign to muonium addition at the outer benzene rings. The third state presents a smaller hyperfine interaction about 25 MHz , and is tentatively assigned to addition at bridging nitrogen atoms. CuPc has an unpaired electron from the Cu atom, which originates a diamagnetic like signal upon muonium addition. The signal exhibits two components with very different relaxation rates, corresponding to two different spatial couplings of the Cu electron with the muonium s electro

Muon diffusion and trapping in chalcopyrite semiconductors

The diffusion parameters of diamagnetic muons in chalcopyrites CuInSe2, CuInS2, CuInTe2, CuGaTe2 and (Ag0.25Cu0.75)InSe2 were obtained by [mu]SR methods. The variations among the different compositions were found to validate the anion-antibonding localization model. The application of a two-state model to the zero-field data revealed muon trapping by defects. The dipolar width at the trap and the number of jumps before trapping were determined. The Cu vacancy is identified as the trapping center in CuInSe2 and the energy depth of the trap has been determined.http://www.sciencedirect.com/science/article/B6TVH-47K37XD-1/1/c6039f1a6212b2c9af977ddf9c54886

Muonium in nano-crystalline II-VI semiconductors

http://www.sciencedirect.com/science/article/B6TVH-4V2NP2J-Y/2/3738c97c2d99528da5d86b486571793

Oxide muonics: A new compendium

A new survey of muonium states brings the total of binary non-magnetic oxides studied to 30, with normal muonium--the interstitially trapped atomic state--found in 15 of these. The number of shallow-donor states of the type known in ZnO now also totals 15, but there are hints of several others. Tantalizingly, the shallow-donor and deep-atomic states are found to coexist in several of the candidate high-permittivity dielectrics. Highly anisotropic states, resembling anomalous muonium in semiconductors and including examples of muonium trapped at oxygen vacancies, complete a spectrum of hyperfine parameters covering five powers of ten. Effective ionization temperatures range from 10 K for shallow to over 1000 K for deep states, with corresponding activation energies between several meV and several eV. The oxide band gap emerges as a parameter controlling the systematics of the deep-to-shallow transition for muonium and, by inference, monatomic hydrogen.http://www.sciencedirect.com/science/article/B6TVH-4HYV078-K/1/89f7584f76f4b62f6fa92e3c5a7d121

Low-energy muon [LEM] study of Zn-phthalocyanine and ZnO thin films

http://www.sciencedirect.com/science/article/B6TVH-4V2NP2J-14/2/e2844eb805cd79148fe2c51116014ae

Spin-exchange of axially symmetric Mu states in polycrystalline media

http://www.sciencedirect.com/science/article/B6TVH-4V2NP2J-11/2/65b0f0e28203effcfd90613c3eeadf2

Detailed hyperfine structure of muoniated radicals in planar phthalocyanines

http://www.sciencedirect.com/science/article/B6TVH-4V2NP2J-20/2/625b6e64a430f4e722e4eec1de4d54a

Dynamics of muoniated radical states in phthalocyanines

This work reports a spectroscopic and spin-dynamics [mu]SR study of the positive muon states formed in the phthalocyanines Zn-Pc, H2-Pc and Cu-Pc. In Zn-Pc and H2-Pc, three distinct muoniated radicals are formed, seen to undergo spin-dynamical processes with charge carriers. Two of the states have very similar hyperfine interaction values, and are believed to be due to muon addition at the outer benzene rings. The third one has a significantly lower hyperfine constant, and is tentatively assigned to addition at an inner part of the molecule. In Cu-Pc, the [mu]SR signals found are diamagnetic-like, and the muon seems to be shielded from interactions with charge carriers and local molecular motion.http://www.sciencedirect.com/science/article/B6TVH-4J2M4HS-2/1/fa04f85559a5018a2b46dc076dec98d