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Register a new userNovel solid state vacuum quartz encapsulated growth of p-Terphenyl: the parent High Tc Oraganic Superconductor (HTOS)
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We report an easy and versatile route for the synthesis of the parent phase of newest superconducting wonder material i.e. p-Terphenyl. Doped p-terphenyl has recently shown superconductivity with transition temperature as high as 120K. For crystal growth, the commercially available p-Terphenyl powder is pelletized, encapsulated in evacuated (10-4 Torr) quartz tube and subjected to high temperature (260C) melt followed by slow cooling at 5C/hour. Simple temperature controlled heating furnace is used during the process. The obtained crystal is one piece, shiny and plate like. Single crystal surface XRD (X-ray Diffraction) showed unidirectional (00l) lines, indicating that the crystal is grown along c-direction. Powder XRD of the specimen showed that as grown p-Terphenyl is crystallized in monoclinic structure with space group P21/a space group, having lattice parameters a = 8.08(2) A, b = 5.62(5) A and c= 13.58(3) A. Scanning electron microscopy (SEM) pictures of the crystal showed clear layered slab like growth without any visible contamination from oxygen. Characteristic reported Raman active modes related to C-C-C bending, C-H bending, C-C stretching and C-H stretching vibrations are seen clearly for the studied p-Terphenyl crystal. The physical properties of crystal are yet underway. The short letter reports an easy and versatile crystal growth method for obtaining quality p-terphenyl. The same growth method may probably be applied to doped p-terphenyl and to subsequently achieve superconductivity to the tune of as high 120K for the newest superconductivity wonder i.e., High Tc Oraganic Superconductor (HTOS).
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Synthesis methodology for flakes of p-terphenyl through sublimation under inert atmosphere of argon is presented. Flake morphology of p-terphenyl provides a favourable environment for efficient intercalation of potassium. Ratio of potassium and p-terphenyl is adjusted so as to obtain the desired superconducting phase i.e. potassium doped p-terphenyl (K3C18H14). A clear transition is observed at 107 K under Zero Field Cooled (ZFC) and Field Cooled (FC) mode. But overall the moment is positive possibly due to impurity phase dominating characteristics in the presence of negligible superconducting volume fraction. The M-H loop taken at 20 K shows magnetic behaviour in synthesized K- doped p-terphenyl but upon background subtraction, it does exhibit characteristics of a type-2 superconductor.
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This paper is published in Advanced Materials (available at http://www3.interscience.wiley.com/cgi-bin/abstract/113511105/ABSTRACT). It has been withdrawn from the cond-mat preprint archive in order to avoid a violation of the Journals policy.
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