Gang Gu

The third-order non-linear optical response of the endohedral metallofullerene Dy@C82

Abstract Dy@C 82 has been prepared by an efficient solvent extraction procedure and characterized by negative-ion desorption chemical ionization mass spectrometry and UV-VIS–near-IR absorption. Degenerate four-wave-mixing measurements on the CS 2 solution of Dy@C 82 were performed using 70 ps laser pulses at 0.532 μm. The magnitude of the second hyperpolarizability γ 1111 of the Dy@C 82 molecule was (3.0±0.5)×10 −30 esu at 0.532 μm. The resonant enhancement and the electron transfer from the trapped dysprosium to the C 82 cage are suggested to bring about its larger non-linear optical response relative to the empty fullerene. The experimental results are in good agreement with our calculations based on an extended Su–Schrieffer–Heeger model and the sum-over-state method.

C60 INDUCED PHOTOLUMINESCENCE OF A SILICA MOLECULAR SIEVE

The optical properties of the regular, 3-nm-wide hexagonal channels of the mesoporous silica molecular sieve (MCM–41) containing C60 are reported. Besides an intensive photoluminescence response at 642 nm from confined C60, a more intensive photoluminescence at 484 nm has been observed, which is considered to result from the passivation of silica zeolite with C60. Our studies indicate that both the properties of guest and host can be modified due to the interaction at the interface of them.

Very intensive red light emission from C60 trapped in 13X molecular sieve

Very intensive red light emission from C60 trapped in 13X molecular sieve has been observed, and it is attributed to the active forbidden transition of C60 anion due to the interaction of C60 with the sketch structure of 13X molecular sieve.

Enhanced photoluminescence of C60 incorporated into interlayers of hydrotalcite

Abstract Strong photoluminescence of sodium-reduced C 60 incorporated into interlayers of hydrotalcite is observed. This phenomenon is correlated to the fact that the reduced C 60 is positioned between positively charged layers of the anion clay. The interaction between the layers and reduced C 60 alters the photophysical properties of C 60 and relaxes the electron transition inhibition, thus enhancing photoluminescence.

Large non-linear absorption in C60 thin films

The non-linear absorption coefficients of C60 thin films at 633 nm were measured with the absolute measurement and the Z-scan method, respectively. Both measurements yield a large non-linear absorption coefficient beta =4.4 cm W-1 and 8.0 cm W-1. A thermal self-focusing effect was also observed. The possible mechanisms of the larger non-linear absorption were discussed. The authors predict that C60 thin film may be a good optical limiter for a continuous wave (CW) laser.

Photoluminescence studies on C60 trapped in NiY zeolite

Abstract Photoluminescence (PL) and photoluminescence excitation (PLE) studies have been performed on C 60 confined in NiY zeolite. Besides the PL peaks of Ni ions a new peak at 544 nm was observed, which is believed to originate from the trapped C 60 within a NiY molecular sieve. From PLE measurements, the transfer of carriers from Ni ions to their adjacent C 60 molecules is deemed to be responsible for the PL and its enhancement, PLE, PL and EPR measurements indicate the coordination of Ni ions on C 60 molecules in supercages of NiY zeolite.

Nearly resonant two‐photon absorption of C60 thin film at 633 nm

We present an absolute measurement of a two‐photon absorption (TPA) coefficient of C60 thin film at 633 nm. Large values of β≊4.4 cm/W were determined. A nearly resonant TPA transition around the 3.76 eV absorption region was discussed.

ENHANCED PHOTOLUMINESCENCE FROM C60 TRAPPED IN NaY MOLECULAR SIEVE

Enhanced photoluminescence from C60 confined in NaY molecular sieve has been observed. The photophysical properties of C60 are modified due to the interaction of C60 with the sketch structure of NaY molecular sieve.

Field induced antiferromagnetic ordering in NiS cluster confined in zeolite Y

An interesting field induced antiferromagnetic ordering in NiS clusters confined in Y molecular sieve was observed. The NiS cluster-zeolite Y composite exhibits an unusual antiferromagnetic ordering state under a magnetic field of 0.724–1.164 T and paramagnetic behavior out of this field region. The antiferromagnetic ordering can be stable up to 180 K. The phenomenon may be understood by the concept of energy level crossing due to intracluster interaction at a certain magnetic field.