12046-08-1Relevant articles and documents
Low temperature synthesis of low thermionic work function (LaxBa1-x)B6
Hasan,Cuskelly,Sugo,Kisi
, p. 67 - 72 (2015/03/31)
This study presents investigations of the microstructure, morphology and emission properties of the promising thermionic material (LaxBa1-x)B6. The material was synthesised by solid-state reaction without post-synthesis purifications. Powder X-ray diffraction revealed that samples prepared at a temperature ≥1500 °C had formed a significant proportion of solid solution (above 54 mass%). Subsequent sintering at 1950 °C caused the formation of a mixture of three solid solutions with the dominant phase being (La0.31Ba0.69)B6 ～85% (by mass). The Richardson work function and emission constant for this boride mixture were found to be 1.03 eV and 8.44 × 10-6 A cm K-2 respectively.
On the existence of solid solutions based on magnesium diboride
Sevast'yanova,Kazin,Kravchenko,Kuz'michev,Ponomarev,Burdina,Bulychev
, p. 1674 - 1680 (2007/10/03)
Dense samples of pure magnesium boride and of the compositions Mg (1-x) AxB2 (A = Na, K, Ca, Sr, Ba, Sn, Ti; 0. 05 2 samples vary only slightly as compared to those of the pure MgB2 irrespective of the sample preparation procedure, high temperature-high pressure treatment conditions, and the amount of dopant, thus indicating the absence of extended solid solution regions. The superconducting transition temperatures of all the samples did not exceed the value characteristic of MgB2 (39±1 K). The results obtained for the dense MgB2 samples using the Andreev reflection and tunneling spectroscopies confirm the two-gap nature of superconductivity in magnesium diboride and point to analogy between the superconductivity mechanisms in this compound and in cuprates.
