Indian Association for the Cultivation of Science

About: Indian Association for the Cultivation of Science is a education organization based out in Kolkata, India. It is known for research contribution in the topics: Catalysis & Excited state. The organization has 3867 authors who have published 10457 publications receiving 220098 citations.

Spin-glass-like state in GdCu: Role of phase separation and magnetic frustration

Abstract: We report investigations on the ground-state magnetic properties of the intermetallic compound GdCu through dc magnetization measurements GdCu undergoes first-order martensitic-type structural transition over a wide temperature window of coexisting phases The high-temperature cubic and the low-temperature orthorhombic phases have different magnetic character and they show antiferromagnetic and helimagnetic orderings below 145 and 45 K, respectively We observe a clear signature of a glassy magnetic phase below the helimagnetic ordering temperature, which is marked by thermomagnetic irreversibility, aging, and memory effects The glassy magnetic phase in GdCu is found to be rather intriguing, with its origin lying in the interfacial frustration due to the distinct magnetic character of the coexisting phases

White light emitting lanthanide based carbon quantum dots as toxic Cr (VI) and pH sensor.

Abstract: Although, great attention is paid to synthesize fluorescent carbon quantum dots (CQDs) for versatile applications, the field remains still attractive to achieve white light using these nano materials. In the present work, CQDs are synthesized from citric acid and lanthanide ions viz. Europium (Eu) and Terbium (Tb) are doped in CQD moiety to explore superior optical response for multifunctional applications. By proper tuning of excitation wavelength, perfect white light with Commission Internationale de l’Elcairage (CIE) index (0.345, 0.344) is obtained using these Europium Terbium co-doped CQDs (Eu-Tb-CQD). The observed photoluminescence of white light emitting lanthanide based CQD is pH dependent and will be used as a visual pH sensor. These luminescent Eu and Tb co-doped CQDs are also very useful to detect toxic Cr (VI) with excellent selectivity and sensitivity as compared to pure CQDs. It shows high quenching efficiency (∼95%) in presence of only 160 µM Cr(VI). The selectivity and lower detection limit are also obtained as ∼80% and 0.175 µM respectively.

Comparison of low-order multireference many-body perturbation theories

Abstract: Tests have been made to benchmark and assess the relative accuracies of low-order multireference perturbation theories as compared to coupled cluster (CC) and full configuration interaction (FCI) methods. Test calculations include the ground and some excited states of the Be, H2,BeH2,CH2, and SiH2 systems. Comparisons with FCI and CC calculations show that in most cases the effective valence shell Hamiltonian (Hv) method is more accurate than other low-order multireference perturbation theories, although none of the perturbative methods is as accurate as the CC approximations. We also briefly discuss some of the basic differences among the multireference perturbation theories considered in this work.