Use of a newly developed compact 2D-ACAR spectrometer for the study of positronium in solids

T. Hyodo, Y. Nagai, H. Saito, Y. Nagashima, A. Vértes, K. Süvegh

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2 Citations (Scopus)


A new 2D-ACAR apparatus has been developed. A pair of compact position-sensitive γ-ray detectors are used, each of which consist of 2.2 × 2.2 × 15 mm3 BGO scintillator blocks bunched into a 25 × 21 array with 2.4 mm pich, and coupled to a position-sensitive photomultiplier tube. The new apparatus has been applied to study the wave functions of the delocalized positronium(Ps) in alkali halides and the localized Ps in complex salt [Zn(ptz)6](BF4)2. It has been observed that all the Bloch Ps satellite peaks in KCl and KI, except for the [200] peaks, are extremely weak. The anisotropies of the Ps wave function in [Zn(ptz)6](BF4)2 changes near the temperature where the Fe analogue of the complex salt exibits spin-crossover transition.

Original languageEnglish
Pages (from-to)488-490
Number of pages3
JournalMaterials Science Forum
Publication statusPublished - Dec 1 1997



  • 2D-ACAR
  • Alkali Halide
  • Complex Salt
  • KCI
  • KI
  • Position Sensitive Detector
  • Positronium
  • Spin-Crossover
  • [Fe(ptz)](BF)
  • [zn(ptz)](BF)

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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