ABSTRACT
We succeeded in growing a new high quality single crystal of a ternary uranium compound UPd2Cd20. From the electrical resistivity, magnetization, magnetic susceptibility, and specific heat experiments, UPd2Cd20 is found to be an antiferromagnetic heavy-fermion compound with the Néel temperature [Formula: see text] = 5 K and exhibits the large electronic specific heat coefficient γ exceeding 500 mJ (K(2)· mol)(-1). This compound is the first one that exhibits the magnetic ordering with the magnetic moments of the U atom in a series of UT2X20 (T: transition metal, X = Al, Zn, Cd). UPd2Cd20 shows typical characteristic features in heavy-fermion systems such as a broad maximum in the magnetic susceptibility at [Formula: see text] and a large coefficient A of T (2) term in the resistivity.
ABSTRACT
We present a new specially designed pressure cell and technique adapted for resistivity measurements in pulsed magnetic fields up to 60 T at pressures up to at least 4 GPa, and temperatures down to 1.5 K. We show that heating effects during the pulse are acceptable (less than 1 K) and can be corrected allowing reliable temperature dependences of the magnetoresistance to be obtained. We illustrate the performance with a study of the phase diagram of the heavy fermion antiferromagnet CeRh2Si2.
ABSTRACT
We have investigated quadrupole effects in tetragonal crystals of PrCu2Si2 and DyCu2Si2 by means of low-temperature ultrasonic measurements. The elastic constant C44 of PrCu2Si2 exhibits pronounced softening below 70 K down to a Néel temperature TN = 20 K, which is described in terms of a quadrupole susceptibility for a Γ5 doublet ground state and a Γ3 singlet first excited state located at 15.6 K in the crystalline electric field scheme. The C44 and C66 of DyCu2Si2 also show softening below 70 K down to TN1 = 9.7 K. A low-lying pseudo-sextet state consisting of three Kramers doublets of Γ6â2Γ7 brings about softening of C44 and C66 in DyCu2Si2.
