01686nas a2200229   4500008004100000022001400041245011100055210006900166260000900235300001100244490000800255520089500263100001801158700002301176700002201199700001901221700002001240700002601260700002401286700001801310856012801328       2019                        eng d  a0031-900700aPressure-induced phase transitions in germanium telluride: raman signatures of anharmonicity and oxidation0 aPressureinduced phase transitions in germanium telluride raman s  cAPR   a1457010 v1223 a<p>Pressure-induced phase transitions in GeTe, a prototype phase change material, have been studied to date with diffraction which is not sensitive to anharmonicity-induced dynamical effects. GeTe is also prone to surface oxidation which may compromise surface sensitive measurements. These factors could be responsible for the lack of clarity about the phases and transitions intervening in the phase diagram of GeTe. We have used high-pressure Raman scattering and ab initio pseudopotential density functional calculations to unambiguously establish the high-pressure phase diagram and identify three phases up to 57 GPa, a low-pressure rhombohedral phase, an intermediate pressure cubic phase, and a high-pressure orthorhombic phase. We detect substantial broadening and softening of Raman modes at low pressure and identify the transition regions and possible intermediate phases.</p>
1 aPawbake, Amit1 aBellin, Christophe1 aPaulatto, Lorenzo1 aBeneut, Keevin1 aBiscaras, Johan1 aNarayana, Chandrabhas1 aLate, Dattatray, J.1 aShukla, Abhay  uhttp://library.ncl.res.in/content/pressure-induced-phase-transitions-germanium-telluride-raman-signatures-anharmonicity-and02451nas a2200229   4500008004100000022001400041245011000055210006900165260000800234300001600242490000700258520164600265100001901911700001701930700002501947700002201972700002001994700002602014700002702040700002902067856012502096       2022                        eng d  a2050-748800aHeterostructure from heteromixture: unusual OER activity of FeP and CoP nanostructures on physical mixing0 aHeterostructure from heteromixture unusual OER activity of FeP a  cNOV  a22354-223620 v103 a<p>
	Heterointerfaces generated by inter-domain interactions on a nanoscale play a critical role in altering the activity of an electrocatalyst towards an electrochemical process. Heterointerfaces affect the surface characteristics, electronic structure, and physicochemical properties of a nanomaterial. Herein, we report an FeP-CoP heterostructure prepared by simple physical mixing of FeP and CoP nanostructures showing a remarkable performance towards water oxidation in comparison to their individual monometallic phosphides. FeP mixed with 20 wt% CoP shows a low overpotential (eta(10)) of 220 mV as compared to FeP (eta(10), 325 mV). Furthermore, a high current density of 1.37 A cm(-2) and mass activity of 18 987 A g(M)(-1) were also achieved at 500 mV overpotential in 1.0 M KOH. The physical mixture shows immense stability for 200 h to achieve a high current density of 200 mA cm(-2). Meanwhile the potentiostatic performance of FeP at 200 mA cm(-2) decreases to an extent of 50% in 40 h. A full cell arrangement employing this catalyst as the anode material requires 1.56 V to attain a current density of 10 mA cm(-2). Various characterization techniques, control experiments and theoretical studies indicate that the formation of heterointerfaces between the nano-domains of FeP and CoP results in charge transfer between Fe and Co metal sites. In addition, an oxygenated surface at the metal phosphide interface favours the sorption kinetics of intermediates involved in the reaction leading to low energy barriers in the potential determining and other steps, thus showing improved performance towards water oxidation.</p>
1 aBhutani, Divya1 aMaity, Sisir1 aChaturvedi, Shashank1 aChalapathi, Divya1 aWaghmare, Umesh1 aNarayana, Chandrabhas1 aPrabhakaran, Vinod, C.1 aMuthusamy, Eswaramoorthy  uhttp://library.ncl.res.in/content/heterostructure-heteromixture-unusual-oer-activity-fep-and-cop-nanostructures-physical