Fluorescence transfer in condensed aromatic hydrocarbons

✍ Scribed by O. Simpson; D.C. Northrop

• Publisher: Elsevier Science
• Year: 1954
• Weight: 247 KB
• Volume: 20
• Category: Article
• ISSN: 0031-8914
• DOI: 10.1016/s0031-8914(54)80251-5

✦ Synopsis

SEMICONDUCTING PROPERTIES OF MIXED CRYSTALS

two lines giving non-conducting compositions, dividing the phase diagram into three regions of different types of conductivity:

• I. manganese conductivity in the presence o~ Cr 3+ and Fe 3+ • ;II chromium conductivity in the presence of Mn 4+ and Fe 3+ III iron conductivity in the presence of Cr 4+ and Mn 4+ In region II with chromium conductivity there is a part where both Cr 3+ and Cr 4+ concentrations are small. The resitivity is high in this part, not because the number of electrons is low but because the path of the electrons is long as it goes only via Cr-ions.

We have tried to use this method to find the place of more elements in the sequence of fourth ionization energies. It is self evident that Ti must be placed before Mn. The determination of the place of Co, however, was difficult as the results of the measurements were complicated by the influence of the ferromagnetic properties on the conductivity 5). These results will be described later.