Drastic change in transport of entropy with quadrupolar ordering in.

The antiferroquadrupolar ordering of is explored by probing thermal and thermoelectric transport. The lattice thermal conductivity drastically increases with the ordering, as a consequence of a large drop in carrier concentration and a strong electron-phonon coupling. The low level of carrier density in the ordered state is confirmed by the anomalously large values of the Seebeck and Nernst coefficients. The results are reminiscent of and suggest that both belong to the same class of partial metal-insulator transitions. The magnitude of the Nernst coefficient, larger than in any other metal, indicates a new route for Ettingshausen cooling at Kelvin temperatures.

[1]  Tatsuo C. Kobayashi,et al.  Pressure-induced metal-insulator transition in the filled skutterudite PrFe4P12 , 2005 .

[2]  H. Sugawara,et al.  Novel Kondo Behaviors Realized in the Filled Skutterudite Structure , 2005 .

[3]  H. Kohno,et al.  Theory of Quasi-Universal Ratio of Seebeck Coefficient to Specific Heat in Zero-Temperature Limit in Correlated Metals(Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties) , 2005, cond-mat/0505471.

[4]  Y. Nakajima,et al.  Thermal transport in the hidden-order state of URu2Si2. , 2004, Physical review letters.

[5]  H. Sugawara,et al.  New High-Field Ordered State in PrFe4P12 , 2004 .

[6]  Y. Kuramoto,et al.  Theory of Crystalline Electric Field and Kondo Effect in Pr Skutterudites( Kondo Effect-40 Years after the Discovery) , 2004, cond-mat/0410461.

[7]  Kamran Behnia,et al.  Thermoelectricity ofURu2Si2: Giant Nernst effect in the hidden-order state , 2004, cond-mat/0407147.

[8]  Y. Nakajima,et al.  Giant Nernst effect in CeCoIn5. , 2004, Physical review letters.

[9]  Kamran Behnia,et al.  On the thermoelectricity of correlated electrons in the zero-temperature limit , 2004, cond-mat/0405030.

[10]  R. W. Hill,et al.  Heat transport as a probe of electron scattering by spin fluctuations: the case of antiferromagnetic CeRhIn(5). , 2004, Physical review letters.

[11]  V. Oganesyan,et al.  Nernst effect, quasiparticles, and d -density waves in cuprates , 2003, cond-mat/0312588.

[12]  H. Sugawara,et al.  Magnetic anisotropy of the heavy fermion state in PrFe4P12 , 2003 .

[13]  H. Sugawara,et al.  Antiferro-Quadrupolar Ordering of 4f-Electron State in the Filled Skutterudite PrFe 4 P 12 , 2003 .

[14]  H. Sugawara,et al.  Crystal-structure modulation in the anomalous low-temperature phase of PrFe4P12 , 2002 .

[15]  H. Harima,et al.  Structural phase transition and anti-quadrupolar ordering in PrFe4P12 and PrRu4P12 , 2002 .

[16]  H. Harima,et al.  Fermi surface instability in Pr-based skutterudites , 2002 .

[17]  E. Bauer,et al.  Superconductivity and heavy fermion behavior in PrOs 4 Sb 12 , 2002 .

[18]  H. Sato,et al.  Anomalous heavy-fermion and ordered states in the filled skutterudite PrFe 4 P 12 , 2002, cond-mat/0201046.

[19]  P. Fischer,et al.  Structural and magnetic properties of RFe4P12 (R=Pr, Nd) studied by neutron diffraction , 2001 .

[20]  H. Sato,et al.  Unusual behaviors in the transport properties of REFe$_{4}$P$_{12}$ (RE: La, Ce, Pr, and Nd) , 2000, cond-mat/0010017.

[21]  K. Abe,et al.  Exotic heavy-fermion state in the filled skutterudite PrFe 4 P 12 uncovered by the de Haas-van Alphen effect , 2000, cond-mat/0010003.

[22]  H. Sato,et al.  Specific-heat anomaly of metamagnetism on PrFe4P12 and UCoAl , 2000 .

[23]  U. Birkholz,et al.  Infinite stage Ettingshausen cooling in Bi‐Sb alloys , 1994 .

[24]  T. Takabatake,et al.  Transport properties of CeNiSn at low temperatures and in high magnetic fields , 1994 .

[25]  C. Marcenat,et al.  Extended transport measurements on high-purity CeB6 , 1990 .

[26]  Maple,et al.  Low-temperature properties of rare-earth and actinide iron phosphide compounds MFe4P12 (M = La, Pr, Nd, and Th). , 1987, Physical review. B, Condensed matter.

[27]  H. Harima,et al.  Theory of Metal-Insulator Transition in Praseodymium Skutterudite Compounds , 2002 .