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Hz, respectively (shown by various open symbols). The onset of superconducting transition is marked by T on c and is independent of the drive frequencies in the range 1 | 111 Hz. In the main inset is shown the TEM image of a single core-shell structure comprising of a ZnS shell encapsulating an In core. The sub-inset panels (a) to (c) shows the EDS maps of the core- shell structure corresponding to the In L-edge, Zn K-edge and S K-edge spectra respectively. The x-ray diffraction for the as prepared samples and the selective area electron diffraction (SAED) of an individual core-shell structure are reported elsewhere [24]. They attest to the single-crystalline nature of the In core. The distribution of length and diameters of the final core-shell structure are sensitive to the exact synthesis conditions. For the sample used in the present study, the average external diameter of the core-shell structure was about 200 nm, with an average diameter of 120 nm for the In nanowire core. The nanowires had a typical length of 5-20 µ m. Using these quantities, an estimate for the amount of Indium present in the sample was done for the purpose of normalizing the magnetization data. For this purpose, the following expression was used: 

<img src='content_image/353022.jpg'>

where, M$_{In}$ is the estimated weight of Indium present in collection of core-shell structures with a total weight M$_{sample}$ , 〈 D$_{ZnS}$ 〉 and 〈 D$_{In}$ 〉 are the average diameters of the ZnS shell and Indium core respectively. Also, ρ$_{ZnS}$ (4.09 gm/cm $^{3}$) and ρ$_{In}$ (7.31 g/cm $^{3}$) are the densities of ZnS and Indium, respectively. Different weights of sample (in the range of 2 to 4 mg) were measured to compare the normalized moment under identical conditions and the estimated normalized moments were identical within experimental resolution suggesting that the core-shell structures are randomly oriented with respect to the field direction. Figure 2 shows the magnetization hysteresis ( M − H ) loops at 2.5 K in the case of a collection of In nanowires (panel (a)), and bulk In cylinder with a diameter 0.9 mm and length 2.1 mm and field perpendicular to the axis of the cylinder (panel (b)). Inset in panel (b) shows an expanded view of a portion of the M − H loop. The notional critical fields, H for c and H ret c , for the forward and the return legs of the M − H loop, respectively are marked. As can be observed in the nanowire case, the critical fields during the field sweep-up and field sweep-down are markedly different. Also, the critical field in the case of the bulk cylinder has a value which lies between H for c and H ret c for the nanowire case. This is remarkably, in contrast to the situation in the case of nanowires of superconducting Pb (reported as a type- 

