4
$\begingroup$

Why the thermoelectric figure of merit is denoted ZT? Does ZT come from the abbreviation of words in some language?

Update: So far T has been figured out --- it is the temperature to make the whole quantity dimensionless. So the question is left only for Z.

$\endgroup$

migrated from physics.stackexchange.com Oct 27 '16 at 6:12

This question came from our site for active researchers, academics and students of physics.

  • 1
    $\begingroup$ Possibly German? $\endgroup$ – Farcher Oct 26 '16 at 6:29
  • $\begingroup$ @Farcher I do not think so. According to Google translation, thermoelektrischen Gütefaktor is corresponding to thermoelectric figure of merit --- the letter "Z" does not even appear in the German word. $\endgroup$ – Alexander Zeng Oct 26 '16 at 7:11
  • $\begingroup$ I guess because German Physicists were very much involved in the foundations of Thermodynamics.. $\endgroup$ – Farcher Oct 26 '16 at 7:50
2
$\begingroup$

My guess for the Z

From THIS Germain-English dictionary, we see that "Figure of merit" in German could be

Gütezahl $\qquad$ or $\qquad$ Leistungskennzahl

in electrical engineering. So probably the letter Z is for Zahl, the German word for "number".

[moral: use Google translate with a grain of salt]

$\endgroup$
  • $\begingroup$ This seems plausible. Just wanted to add that the Z might also come from the word Ziffer (as in thermoelektrische Kennziffer which translates to thermoelectric indicator). Ziffer is a synonym for Zahl that is perhaps more frequently used in the sciences and engineering. (Disclaimer: I'm German.) $\endgroup$ – Casimir Jan 21 at 14:06
1
$\begingroup$

The concept of the thermoelectric figure of merit and the abbreviation ZT were introduced by the Russian physicist Abram Fedorovich Ioffe in 1949, so I assume the acronym originates from Russian. However all the references I can find are behind paywalls so frustratingly I cannot tell you how ZT is derived.

If your university has access to it, Ioffe's book where all this is described is Ioffe AF (1957) Semiconductor thermoelements, and Thermoelectric cooling.

$\endgroup$
  • $\begingroup$ In that book, it is just denoted as a lowercase "z", rather than the uppercase "ZT". $\endgroup$ – Alexander Zeng Oct 27 '16 at 6:06
  • $\begingroup$ While according to Goldsmid, H. J. Introduction to Thermoelectricity, Springer-Verlag Berlin Heidelberg, 2016, "ZT" is dimensionless, and "T" there means temperature. $\endgroup$ – Αλέξανδρος Ζεγγ Oct 27 '16 at 6:16
  • $\begingroup$ @AlexanderZeng: I've seen it as both zT and ZT. I don't know how Ioffe used it because I don't have access to his papers. $\endgroup$ – John Rennie Oct 27 '16 at 6:23
  • $\begingroup$ So the point is, you take the original figure of merit $Z$ and multiply by tempurature $T$ to make it dimensionless. The result is $ZT$. So half the answer is "$T$ stands for tempurature". Now we just need to know where $Z$ comes from. $\endgroup$ – Gerald Edgar Oct 27 '16 at 15:03
  • $\begingroup$ It cannot be a Russian acronym. In Russian a "thermoelectric figure of merit" is "термоэлектрическая добротность". Nothing resembles Z or З, neither graphically nor phonetically. $\endgroup$ – user58697 Oct 28 '16 at 3:10

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.