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Abstract The crystal structure, electron energy-loss spectroscopy (EELS), heat capacity, and anisotropic magnetic and resistivity measurements are reported for Sn flux grown single crystals of orthorhombic Pr2Co3Ge5(U2Co3Si5-type,Ibam). Our findings show thato-Pr2Co3Ge5hosts nearly trivalent Pr ions, as evidenced by EELS and fits to temperature dependent magnetic susceptibility measurements. Complex magnetic ordering with a partially spin-polarized state emerges nearTsp= 32 K, with a spin reconfiguration transition nearTM= 15 K. Heat capacity measurements show that the phase transitions appear as broad peaks in the vicinity ofTspandTM. The magnetic entropy further reveals that crystal electric field splitting lifts the Hund’s rule degeneracy at low temperatures. Taken together, these measurements show that Pr2Co3Ge5is an environment for complexfstate magnetism with potential strongly correlated electron states.
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An Unusual Fullerene–Carbene Adduct: Thermal Motion, Disorder, or Both?**
Abstract A single‐crystal X‐ray study of a fullerene‐imidazole adduct at nine temperatures (80 K≤T≤480 K), accompanied by energy calculations, strongly suggested thermal motion of the C60moiety with respect to the imidazolium heterocycle. Analysis of the anisotropic displacement parameters, calculations of frequencies, and the refinement of disorder models for the crystal at four temperatures (230 K≤T≤380 K) lead to the conclusion that the rotator is moving at all temperatures. The rotation barrier is low, with one preferred crystallographic site and several other energy minima.
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- Award ID(s):
- 2203519
- PAR ID:
- 10394841
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Helvetica Chimica Acta
- Volume:
- 106
- Issue:
- 2
- ISSN:
- 0018-019X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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