We have determined the physical ground state properties of the compounds CeRuPO and CeOsPO by means of magnetic susceptibility χ(T ), specific heat C(T ), electrical resistivity ρ(T ), and thermopower S(T ) measurements. χ(T ) reveals a trivalent 4f 1 cerium state in both compounds. For CeRuPO a pronounced decrease of ρ(T ) below 50 K indicates the onset of coherent Kondo scattering, which is confirmed by enhanced S(T ). The temperature and magnetic field dependence of χ(T ) and C(T ) evidence ferromagnetic (FM) order at T C = 15 K. Thus, CeRuPO seems to be one of the rare example of a FM Kondo lattice. In contrast, CeOsPO shows antiferromagnetic order at T N = 4.4 K despite only minor changes in lattice parameters and electronic configuration. Additional 31 P NMR results support these scenarios. LSDA+U calculations evidence a quasi two dimensional electronic band structure, reflecting a strong covalent bonding within the CeO and RuP layers and a weak ionic like bonding between the layers.

Single crystals of three-dimensional (3D) C60 polymer were prepared by the topotactic conversion of two-dimensional (2D) C60 polymer single crystals at a pressure of 15 GPa at 600 degrees C. The x-ray single crystal study revealed that the 3D C60 polymer crystallized in a body centered orthorhombic space group Immm, and spherical C60 monomer units were substantially deformed to rectangular parallelepiped (cuboidal) shapes, each unit being bonded to eight cuboidal C60 neighbors via [3 + 3] cycloaddition. The 3D C60 polymer was electron conductive, in contrast with the nonconductive behavior of 2D polymers.

We have synthesized polycrystalline Sr2IrO4 and measured its magnetic susceptibility, electrical resistivity, specific heat, Seebeck coefficient, and thermal conductivity. The magnetic susceptibility χ(T) shows a ferromagnetic transition at 250 K while the behaviour above the transition temperature is well described by a Curie–Weiss fit with a small effective moment μeff = 0.33 μB and a paramagnetic Curie–Weiss temperature, θCW = +251 K, consistent with previous studies on this compound. However, specific heat, Seebeck coefficient, and thermal conductivity are all dominated by the phonon contribution and show no anomalies at the ferromagnetic transition. Electrical resistivity, unlike the single crystal, shows a huge increase, three orders of magnitude, with decreasing temperature. The temperature dependence of resistivity is logarithmic at high temperatures (210 K

We have reinvestigated the magnetic properties of Zn2VO(PO4)2 by means of magnetic susceptibility χ(T) and specific heat Cp(T) measurements performed on polycrystalline samples. At high temperatures χ(T) follows a Curie–Weiss law with the effective moment expected for a V4+, S = 1/2 ion, while a rounded maximum in χ(T) at 6.95 K and a hump in Cp(T) around 4.5 K indicate the onset of antiferromagnetic correlations at low temperatures. Finally, a kink in χ(T) and a well defined mean-field anomaly in Cp(T) at TN = 3.7 K evidence a transition into an ordered antiferromagnetic state. A comparison of χ(T) and of the magnetic contribution Cpmagn(T) to the specific heat with theoretical predictions indicates that the magnetic lattice of this compound corresponds to a square lattice rather than the spin chain proposed in an earlier report. The results of quantum Monte Carlo calculations for a square lattice agree very well down to TN with Cpmagn(T) extracted from our experiment, while finite size calculations overestimate the specific heat in the region of the maximum in Cpmagn(T).