IMPACT OF A JAHN-TELLER-LIKE CORRELATION COUPLING ON THE PROPERTIES OF MIXED-VALENT SMB6

In previous studies a new type of Jahn-Teller coupling in doped SmB6 w as presented both in a molecular and in an extended semiconductor mode l. The conventional role of configurational distortions is taken over by a symmetry-adapted electronic-correlation coupling, which takes adv antage of the electronic properties of the host crystal. Within this m odel electron spin-resonance measurements of the systems SmB6:Gd3+ and SmB6:Er3+ can be explained in a natural way. In this paper we examine the impact of this coupling-type on the properties of the band states . This results in a strong ''softening'' of the band states at the edg e of the semiconducting gap and a contribution to the specific heat, w hich could serve as an additional experimental pro of for the unconven tional mechanism. [S0163-1829(98)04340-9].