Abstract: An active material for the manufacture of laser rods, having the chemical composition expressed by the formula A.sub.1+x B.sub.1-y C.sub.3-x O.sub.7-0.5 x, wherein A is barium, strontium, calcium, or a mixture thereof; B is lanthanum, yttrium, or a mixture thereof; C is gallium, aluminum, or a mixture thereof; and x and y assume both positive and negative values from -0.12 to +0.12;; and as a dopant an active element chosen from the group consisting of praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, erbium, thulium and ytterbium in an amount of from 0.02 to 8.33 atomic percent.

Abstract: The subject of the invention is an alloy of magnetostrictive and piezomagnetic properties suitable for the production of cores of ultrasonic transducers. The alloy according to the invention contains, besides iron, 5 to 15% Al, 0.5 to 10% Co and up to 3% of other additives.