Lutetium superconducting

The light lanthanides also exhibit some unusual electrical and magnetic properties. The superconductivity of lanthanum has already been mentioned. But when its behavior is compared to the superconductivity in scandium, yttrium and lutetium, we find lanthanum is unusual. The ordering temperature T, and pressure dependence of T are both larger in lanthanum than in the other three superconductors (see section 3.7.3 and fig. 12a). 

Fig. 12. The pressure dependences of the superconductivity transition temperatures of several rare earth elements (a) lanthanum, lutetium, scandium and yttrium (after Wittig et al. 1979) and (b) cerium (after Probst and Wittig 1978).

The critical pressure, at which superconductivity begins (i.e. 7, = OK), is consistent with the Zspi values for these three metals. That is, the Pc of lutetium and yttrium are about the same, but significantly lower than that of scandium (fig. 12a), and 2jpj for yttrium and lutetium are nearly the same and about 3 to 4 times lower than 2spi for scandium. This supports the above analysis that the absence of superconductivity in lutetium, scandium and yttrium is due to spin fluctuations in these metals. 

Fig. 10.12. vs. pressure for lutetium. The numbers indicate the sequence of 11 measurements for one particular sample. As seen, is a reversible function of pressure. Two arrows indicate that no superconductivity was detected at those pressures down to — 20 mK. The curve is a smooth fit of the data (Probst, 1974). 

Anderson et al. (1958) measured the effect of lutetium additions on the superconducting transition temperature of lanthanum and reported that alloys containing 55 and 80 at% La each had the lanthanum dhcp structure. These results are consistent with those reported above by Lundin. 

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