Thermal expansion and magnetostriction of clathrate compound Pr3Pd20Ge6

In Pr3Pd20Ge6, the Pr ions are located at two different crystallographic sites, 4a and 8c site. Antiferro-quadrupole ordering (AFQ) of the 8c site occurs at 250 mK. Ac susceptibility measurement indicated that antiferromagnetic ordering (AFM) of the 4a site and Hyperfine-enhanced Pr nuclear magnetic ordering of the 8c site occur at 77 and 9 mK, respectively. To clarify the magnetic and quadrupole properties of Pr3Pd20Ge6, thermal expansion and magnetostriction measurements on single crystal sample were carried out along the [001] direction up to 8 T down to 500 μK using a capacitive dilatometer. In zero field, relative length change ΔL/L in [001] direction had a dip at AFQ and abrupt decrease at AFM ordering. From thermal expansion and isothermal magnetostriction measurements, magnetic phase diagram of Pr3Pd20Ge6 along [001] direction was obtained.

[1]  M. Akatsu,et al.  Magnetic ordering of hyperfine-coupled nuclear and4f-electron moments in the clathrate compoundPr3Pd20Ge6 , 2014 .

[2]  M. Akatsu,et al.  Role of hyperfine coupling in magnetic and quadrupolar ordering of Pr3Pd20Si6. , 2013, Physical review letters.

[3]  S. Abe,et al.  A compact capacitive dilatometer for thermal expansion and magnetostriction measurements at millikelvin temperatures , 2012 .

[4]  M. Akatsu,et al.  Quadrupole Ordering and Rattling Motion of Clathrate Compound Pr3Pd20Ge6 , 2012 .

[5]  S. Abe,et al.  Novel quantum criticality in CeRu2Si2 near absolute zero observed by thermal expansion and magnetostriction. , 2008, Physical review letters.

[6]  Nemoto Yuichi,et al.  Rattling in Clathrate Compounds of ROs4Sb12 and R3Pd20Ge6 , 2008 .

[7]  G. Kido,et al.  Magnetic properties of clathrate-like compound Pr3Pd20Ge6 , 2006 .

[8]  R. Shiina.  Remark on high-field phase diagram of CeB6 , 2002 .

[9]  M. Yokoyama,et al.  Antiferro-Quadrupolar Ordering and Multipole Interactions in PrPb3 , 2001 .

[10]  K. Ohoyama,et al.  Antiferroquadrupolar Ordering and Magnetic Properties of the Tetragonal DyB 2C 2 Compound , 1999 .

[11]  L. Keller,et al.  Crystalline electric field excitations in R3Pd20Ge6 (R=Ce, Pr, Nd) , 1999 .

[12]  T. Matsumura,et al.  Quadrupolar ordering in TmTe , 1996 .

[13]  S. Kunii,et al.  Magnetic phase diagram of CeB6 , 1985 .

[14]  D. Davidov,et al.  "Reverse" Magnetostriction Effects in the [001] Shape Magnetostriction of Ce_{x}La_{1-x}Sb and Sm_{x}La_{1-x}Sb Single Crystals , 1982 .