We have examined the double-beta decay mode accompanied by Majoron emission. After 223 days of measurement corresponding to about 615 kg d or 19.3 mol yr of exposure we find a lower half-life limit for this decay channel of ${\mathit{T}}_{1/2}^{0\nu \mathrm{\chi }}$>1.66(1.99)×${10}^{22}$ yr [90% (68%) C.L.] yielding a new limit for the Majoron-neutrino coupling of 〈${\mathit{g}}_{\nu \mathrm{\chi }}$〉<1.8×${10}^{\mathrm{-}4}$ (90% C.L.).

• Received 6 April 1993

DOI:https://doi.org/10.1103/PhysRevLett.70.2853