Terbium-iron alloys

The discovery in 1976 of magneto-optic materials based on the rare earth/transition metal (RE/TM) alloys (Choudhari et al., 1976) provided a practical material system for rewritable magneto-optic recording. These materials were amorphous and thus allowed acceptable signal-to-noise ratio to be obtained. Most commercial magneto-optic films today are based on terbium iron cobalt (TbFeCO). 

Silvery metal, that can be cut with a knife. Terbium alloys and additives are widely used in optoelectronics to burn CDs as well as in laser printers. The pronounced magnetostriction (Joule effect) makes "terfenol-D" (terbium-dysprosium-iron) indispensable in sonar technology. The physics of the element appears to be more interesting than its chemistry, in which it is rarely used in catalysis. 

Terephthaloyl chlorides (TCL), 29 715 polycondensation, 7 635 polymers derived from, 23 730 TERFENOL-D (terbium dysprosium iron alloy), 22 714 TERGITOL, 2 43... 

Markova et al. (1967) investigated the terbium-yttrium system by means of microscopy, X-ray diffraction, thermal analysis, hardness and electrical resistance measurements. Their starting materials were distilled yttrium of 99.6 to 99.7 (wt )% purity and terbium of 98.5 to 99% purity. Impurities in their terbium included yttrium, gadolinium, dysprosium, calcium, copper, iron and tantalum. Both metals contained gaseous impurities. Alloys were melted in an arc furnace under a helium atmosphere and annealed at 850°C for 70hr. 

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