TY - JOUR
T1 - Pressure, substitution, and magnetic-field dependence of the valence phase transition in Yb0.4In0.6Cu2
AU - Nowik, I.
AU - Felner, I.
AU - Voiron, J.
AU - Beille, J.
AU - Najib, A.
AU - Du Tremolet De Lacheisserie, E.
AU - Gratz, G.
PY - 1988
Y1 - 1988
N2 - Magnetization, resistivity, thermal expansion coefficient, and x-ray unit-cell measurements of Yb0.4In0.6Cu2 under pressure (P up to 25 kbar) and in magnetic fields (Hext up to 180 kOe) at temperatures 4.2-80 K have been performed. The valence-phase-transition temperature, Tv, is pressure dependent and surprisingly enough also field dependent. One obtains dTv/dP=-2.1 K/kbar for P<6 kbar. Negative chemical pressure obtained by substituting Yb by La or Cu by Ag increases Tv. A theoretical analysis within a previously published model shows that the interconfigurational excitation energy below Tv changes with pressure at a rate dE0/dP=-11 K/kbar. The external magnetic field does not affect E0, but it increases the Yb3+ excited-state population and thus drives the phase transition to a lower temperature at a rate dTv/dHext=-0.022 K/kOe.
AB - Magnetization, resistivity, thermal expansion coefficient, and x-ray unit-cell measurements of Yb0.4In0.6Cu2 under pressure (P up to 25 kbar) and in magnetic fields (Hext up to 180 kOe) at temperatures 4.2-80 K have been performed. The valence-phase-transition temperature, Tv, is pressure dependent and surprisingly enough also field dependent. One obtains dTv/dP=-2.1 K/kbar for P<6 kbar. Negative chemical pressure obtained by substituting Yb by La or Cu by Ag increases Tv. A theoretical analysis within a previously published model shows that the interconfigurational excitation energy below Tv changes with pressure at a rate dE0/dP=-11 K/kbar. The external magnetic field does not affect E0, but it increases the Yb3+ excited-state population and thus drives the phase transition to a lower temperature at a rate dTv/dHext=-0.022 K/kOe.
UR - http://www.scopus.com/inward/record.url?scp=24844433939&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.37.5633
DO - 10.1103/PhysRevB.37.5633
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AN - SCOPUS:24844433939
SN - 0163-1829
VL - 37
SP - 5633
EP - 5638
JO - Physical Review B
JF - Physical Review B
IS - 10
ER -