We have investigated low-temperature elastic properties of PrMg3 with a non-Kramers Γ3 doublet ground state by using ultrasonic measurements under high field up to 18 T down to 20 mK. A softening of the elastic constant (C11-C12)/2 has been observed below 8 K due to the non-magnetic Γ3 doublet possessing electric quadrupole Ou and Ov with Γ3 symmetry and magnetic octupole Txyz with Γ2. This result appreciably is deviated from a theoretical fitting of the quadrupole susceptibility based on the crystal-electric-field levels below 800 mK. Furthermore, the (C11-C12)/2 shows strange magnetic dependence up to 18 T below 1.7 K, which are inconsistent with the theoretical results.
ASJC Scopus subject areas
- Physics and Astronomy(all)