@article {45978,
	title = {Identification of the Zn substitution sites in La-Zn substituted SrAl12O19 from Al-27 solid-state NMR studies},
	journal = {Journal of the American Ceramic Society},
	volume = {97},
	year = {2014},
	month = {SEP},
	pages = {2990-2995},
	type = {Article},
	abstract = {<p>The La-Zn substituted hexagonal strontium aluminate, Sr1-xLaxAl12-xZnxO19, with the magnetoplumbite structure and having five different coordination environments for Al with different symmetries, is investigated using Al-27 solid-state NMR to get detailed information on the sites of substitution of Zn and the associated changes in the local coordination environments of Al. The objective of the study was to get information on the local structural variations in the isostructural La-Co substituted strontium ferrite, Sr1-xLaxFe12-xCoxO19, showing enhanced magnetic performance on substitution. The NMR studies on the aluminate give direct evidence for the sites of substitution and the changes in the local coordination environments. It is found that Zn is substituted at the 2a and 4f(2) AlO6 octahedral sites. However, an interesting observation from the NMR studies is the stabilization of the Al site occupancy at the penta-coordinated 2b site over the distorted tetrahedral 4eAl site, without any substitution at these sites. Large changes in the quadrupolar coupling constant of the 2a and 4e sites are observed between x=0.2 and 0.3, corresponding to the compositional region showing higher performance in the case of Sr1-xLaxFe12-xCoxO19, indicating the role of distortion of local coordination environments on suitable substitution in controlling the performance parameters.</p>},
	issn = {0002-7820},
	doi = {10.1111/jace.13029},
	author = {Baby, Bindhu and Dey, Krishna K. and Ajithkumar, Thalasseril G. and Joy, Pattayil A.}
}
@article {46714,
	title = {Integrating structurally perfect s=1/2 kagome-lattice with reduced graphene oxide},
	journal = {Journal of Physical Chemistry C},
	volume = {124},
	year = {2020},
	month = {SEP},
	pages = {19753-19759},
	type = {Article},
	abstract = {<p>S = 1/2 kagome-lattice hydroxychlorides are promising candidates for realizing the elusive quantum spin liquid (QSL) state. Herbertsmithite [Cu3Zn(OH)(6)Cl-2], a naturally occurring hydroxychloride mineral from the class of atacamites {[Cu-4-xMx(OH)(6)X-2] where M = Zn, Cu, Co, Ni and X = Cl, Br, I}, is one of the most appealing systems to study the QSL state because of the presence of a structurally perfect S = 1/2 kagome-lattice. It is an electrical insulator. However, realizing phase-pure herbertsmithite without imposing harsh reaction conditions remained synthetically challenging. In this work, for the first time, we have synthesized phase-pure herbertsmithite as well as its structural analogue paratacamite, [ZnxCu4-x(OH)(6)Cl-2; 0.33 = x \&lt; 1], at ambient reaction conditions. Furthermore, taking graphene oxide (GO) as an additional precursor in the reaction mixture, we have successfully integrated phase-pure crystallites of herbertsmithite (H) and paratacamite (P) with nanosheets of semiconducting and diamagnetic reduced graphene oxide (rGO) by in situ oxidation-reduction reaction. The isolated H-rGO and P-rGO systems were found to be magnetic semiconductors inheriting strong spin frustration from H and P, and semiconductivity from rGO. The H-rGO system in particular exhibited negative Seebeck coefficient (n-type semiconductor) with a thermoelectric power factor of 0.1 mu W center dot m(-1)center dot K-2 at 400 K. We anticipate the simple chemical principles outlined in this work to be useful for studying a variety of complex QSLs including electron doping. Also, semiconducting and rather unconventional materials of such metal oxochlorides with rGO isolated here need further exploration in view of thermoelectric applications.</p>
},
	issn = {1932-7447},
	doi = {10.1021/acs.jpcc.0c06564},
	author = {Gupta, Kriti and Dadwal, Arun and Ninawe, Pranay and Joy, Pattayil A. and Ballav, Nirmalya}
}
