We present ultrasonic (ν) and specific heat (cp) measurements performed on La1.67Sr0.33NiO4 to confirm and characterize the nature of the thermodynamic transition observed at Tc = 240K in this material. The behavior of ν(T ∼ Tc) suggests that this transition is not due to the long-range ordering of the uncompensated nickel spins. The possibility of independent hole-spin behavior is consistent with the observed entropy and measured anomalies in the resistivity, susceptibility, and ultrasound. A comparison of ν(T) and cp(T) suggests that the sound couples primarily to the order parameter energy.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)