Mohapatra, Niharika, Iyer, Kartik K, Rayaprol, Sudhindra, Jammalamadaka, S. Narayana, Sampathkumaran, E. V.
The influence of negative chemical pressure induced by gradual replacement of Ca by Sr as well as of external pressure (up to 10 kbar) on the magnetism of Ca3CoRhO6 has been investigated by...
Paulose, P. L., Mohapatra, Niharika, Sampathkumaran, E. V.
We report the results of 151Eu Moessbauer effect and magnetization measurements in the Eu-doped Ca3Co2O6 and Ca3CoRhO6, which are of great current interest in the fields of spin-chain magnetism and...
Magnetic behavior of nanocrystalline LaMn2Ge2 (2008)
Jammalamadaka, S. Narayana, Das, Sitikantha D, Chalke, B. A., Sampathkumaran, E. V.
The compound, LaMn2Ge2, crystallizing in ThCr2Si2-type tetragonal crystal structure, has been known to undergo ferromagnetic order below (T_C=) 326 K. In this article, we report the magnetic behavior...
Magnetic Anomalies in a New Manganocuprate Gd3Ba2Mn2Cu2O12 (2008)
Rayaprol, Sudhindra, Singh, Kiran, Gaur, N. K., Jammalamadaka, S. Narayana, Mohapatra, Niharika, Sampathkumaran, E. V.
The manganocuprate compound Gd3Ba2Mn2Cu2O12 (Gd-3222) has been synthesized by conventional solid state reaction method and its magnetic behavior has been studied by dc and ac magnetization (M) and...
Jammalamadaka, S. Narayana, Sampathkumaran, E. V., Murthy, V. Satya Narayana, Markandeyulu, G.
The Laves phase compound, YCo2, is a well-known exchange-enahnced Pauli paramagnet. We report here that, in the nanocrystalline form, this compound interestingly is an itinerant ferromagnet at room...
Patil, Swapnil, Iyer, Kartik K, Maiti, K., Sampathkumaran, E. V.
The results of magnetic susceptibility, electrical resistivity (rho), and heat capacity measurements as a function of temperature are reported for the alloys, Ce2Rh(1-x)Co(x)Si3, crystallizing in an...
Magnetic phase transition and magnetocaloric effect in PrCo9Si4 and NdCo9Si4 (2007)
Mohapatra, Niharika, Sampathkumaran, E. V.
The compounds, PrCo9Si4 and NdCo9Si4, have been recently reported to exhibit first-order ferromagnetic transitions near 24 K. We have subjected this compound for further characterization by...
Large magnetocaloric effect in Gd4Co3 (2007)
Mohapatra, Niharika, Iyer, Kartik K, Sampathkumaran, E. V.
We report a large entropy change (DeltaS) below 300 K, peaking near TC= 220 K, due to isothermal change of magnetic field, for Gd4Co3, with a refrigeration capacity higher than that of Gd. Notably,...
Magnetic anomalies in single crystalline ErPd2Si2 (2007)
Sampathkumaran, E. V., Mohapatra, Niharika, Iyer, Kartik K, Cao, C. D., Loeser, W., Behr, G.
Considering certain interesting features in the previously reported 166Er Moessbauer effect and neutron diffraction data on the polycrystalline form of ErPd2Si2 crystallizing in ThCr2Si2-type...
Nakano, T., Sengupta, Kausik, Rayaprol, Sudhindra, Hedo, M., Uwatoko, Y., Sampathkumaran, E. V.
The competition between magnetic ordering and the Kondo effect in Ce2RhSi3, ordering antiferromagnetically at 7 K, is investigated by the measurements of magnetization, heat capacity and electrical...
Singh, R. S., Medicherla, V. R. R., Maiti, Kalobaran, Sampathkumaran, E. V.
We report the observation of an unusual behavior of highly extended 5d electrons in Y2Ir2O7 belonging to pyrochlore family of great current interest using high resolution photoemission spectroscopy....
Bremsstrahlung-Isochromat Study of Unoccupied Electronic States in Repd3 Compounds (2007)
Laubschat, C., Kaindl, G., Sampathkumaran, E. V., Schneider, W. D.
Geometrically frustrated magnetic behavior of Sr3NiRhO6 and Sr3NiPtO6 (2007)
Mohapatra, Niharika, Iyer, Kartik K, Rayaprol, Sudhindra, Sampathkumaran, E. V.
The results of ac and dc magnetic susceptibility isothermal magnetization and heat-capacity measurements as a function of temperature (T) are reported for Sr3NiRhO6 and Sr3NiPtO6 containing magnetic...
Superconducting behavior of the solid solution, Y2Pd(1-x)Pt(x)Ge3 (2007)
Iyer, Kartik K, Sampathkumaran, E. V.
The compound Y2PdGe3 was earlier reported by us to be one of the very few ternary superconducting compounds (T_c= 3 K) belonging to the same structure as that of MgB2. Here we report the results of...
Mohapatra, Niharika, Sampathkumaran, E. V.
The compound, Ca3CoRhO6, containing magnetic Co-Rh chains intervened by Ca ions, has been known to be one of the few exhibiting partially disordered antiferromagnetic structure (PDA) due to...
Sampathkumaran, E. V., Mohapatra, Niharika, Rayaprol, Sudhindra, Iyer, Kartik K
We report the results of ac and dc magnetic susceptibility (chi), heat-capacity (C), isothermal magnetization and isothermal remanent magnetization measurements on the compound, Sr3CuRhO6,...
Sengupta, Authors Kausik, Iyer, Kartik K, Sampathkumaran, E. V.
The results of dc magnetization, electrical and magnetoresistance and heat capacity measurements (2-300 K) on Tb7Rh3, crystallizing in Th7Fe3-type hexagonal structure, are reported. In this compound,...
An anomalous magnetic phase transition at 10 K in Nd7Rh3 (2006)
Sengupta, Kausik, Sampathkumaran, E. V.
The compound, Nd7Rh3, crystallizing in Th7Fe3-type hexagonal structure, has been shown recently by us to exhibit a signature of magnetic phase-coexistence phenomenon below 10 K after a field cycling,...
Single-ion Kondo behavior of a novel Kondo lattice, CeNi9Si4 (2006)
Sengupta, Kausik, Sampathkumaran, E. V.
The compound, CeNi9Si4 has been recently reported to be an unusual Kondo lattice with a large Ce-Ce separation, with a breakdown of Kadowaki-Woods relationship governing low temperature electrical...
Sengupta, Kausik, Sampathkumaran, E. V.
The compound, Nd7Rh3, crystallizing in Th7Fe3-type hexagonal structure, was previously known to exhibit two magnetic transitions, one at 32 K and the other at 10 K (in zero magnetic field). Here, we...
Rayaprol, S., Sampathkumaran, E. V.
The magnetic behavior of a solid solution, Ca3-xYxCo2O6, based on an exotic spin-chain compound, Ca3Co2O6, crystallizing in K4CdCl6-derived rhombohedral structure is investigated. Among the...
Large magnetoresistance and magnetocaloric effect above 70 K in Gd2Co2Al, Gd2Co2Ga and Gd7Rh3 (2005)
Sengupta, Kausik, Iyer, Kartik K., Sampathkumaran, E. V.
The electrical resistivity, magnetization and heat-capacity behavior of the Gd-based compounds, Gd2Co2Al, Gd2Co2Ga and Gd7Rh3, ordering magnetically at TC= 78 K, TC= 76 K and TN= 140 K have been...
Sengupta, Kausik, Paulose, P. L., Sampathkumaran, E. V., Doert, Th., Jemetio, J. P. F.
The Eu-based compound, EuCu2As2, crystallizing in the ThCr2Si2-type tetragonal structure, has been synthesized and its magnetic behavior has been investigated by magnetization (M), heat-capacity (C)...
Maiti, Kalobaran, Singh, Ravi Shankar, Medicherla, V. R. R., Rayaprol, S., Sampathkumaran, E. V.
We investigate the origin of charge density wave (CDW) formation in insulators by studying BaIrO3 using high resolution (1.4 meV) photoemission spectroscopy. The spectra reveal the existence of...
Magnetic behavior of the spin-chain compounds,Ca3CuIrO6 and Ca3CuRhO6 (2004)
Rayaprol, S., Sampathkumaran, E. V.
The spin-chain compounds, Ca3CuIrO6 and Ca3CuRhO6, crystallizing in a K4CdCl6-derived monoclinic structure, are investigated by ac and dc magnetization, isothermal remnant magnetization as well as...
A transition from antiferromagnetism to spin-glass freezing in single crystalline, Dy2PdSi3 (2004)
Iyer, K. K., Paulose, P. L., Sampathkumaran, E. V., Bitterlich, H., Behr, G.
We report low temperature (1.8-15 K) ac magnetic susceptibility and isothermal remanent magnetization behavior for the single crystalline form of Dy2PdSi3, crystallizing in a AlB2-derived hexagonal...
Nature of magnetism in the spin-chain compound, Ca3CuRuO6 (2004)
Rayaprol, S., Sampathkumaran, E. V.
A quasi one-dimensional compound, Ca3CuRuO6, has been synthesized by solid-state reaction method and studied using magnetization (M) and heat capacity (C) measurements. This compound undergoes...
Sengupta, Kausik, Rayaprol, S., Sampathkumaran, E. V.
We report the response of electrical resistivity $\rho$ to the application of magnetic fields (H) up to 140 kOe in the temperature interval 1.8-300 K for the compound, Gd7Rh3, ordering...
Large magnetoresistance anomalies in Dy7Rh3 (2004)
Sengupta, Kausik, Rayaprol, S., Sampathkumaran, E. V.
The compound Dy7Rh3 ordering antiferromagnetically below (TN=) 59 K has been known to exhibit a temperature (T) dependent electrical resistivity (rho) behavior in the paramagnetic state unusual for...
Novel magnetic behavior of single crystalline Er2PdSi3 (2004)
Iyer, K. K., Paulose, P. L., Sampathkumaran, E. V., Frontzek, M., Kreyssig, A., Doerr, M., ...
We report the results of ac and dc magnetic susceptibility (chi) and electrical resistivity (rho) measurements on the single crystals of Er2PdSi3, crystallizing in an AlB2-derived hexagonal...
Inhomogeneous magnetic behavior of Pr0.7Ca0.3CoO3 and Nd0.7Ca0.3CoO3 (2004)
Kundu, Asish K., Sampathkumaran, E. V., Gopalakrishnan, K. V., Rao, C. N. R.
Unlike La0.7Ca0.3CoO2.97, Pr0.7Ca0.3CoO3 and Nd0.7Ca0.3CoO2.95 do not show distinct ferromagnetic transitions, but instead they exhibit very low magnetic moments down to 50 K. A detail study of...
Electrical resistivity and tunneling anomalies in CeCuAs2 (2004)
Sampathkumaran, E. V., Ekino, T., Ribeiro, R. A., Sengupta, Kausik, Nakano, T., Hedo, M., ...
The compound CeCuAs2 is found to exhibit negative temperature (T) coefficient of electrical resistivity (rho) under ambient pressure conditions in the entire T-range of investigation (45 mK to 300...
Sampathkumaran, E. V., Hiroi, Z., Rayaprol, S., Uwatoko, Y.
Heat-capacity behavior in the presence of externally applied magnetic field (H) up to 140 kOe is investigated (2-35 K) for the quasi-1-dimensional compound, Ca3Co2O6, believed to order magnetically...
High pressure effects on the electrical resistivity behavior of the Kondo lattice, YbPd2Si2 (2004)
Nakano, T., Hedo, M., Uwatoko, Y., Sampathkumaran, E. V.
We report the influence of external pressure (P= up to 8 GPa) on the temperature dependence of electrical resistivity of a Yb-based Kondo lattice, YbPd2Si2, which does not undergo magnetic ordering...
Magnetic, electrical resistivity, heat-capacity and thermopower anomalies in CeCuAs2 (2004)
Sengupta, Kausik, Sampathkumaran, E. V., Nakano, T., Hedo, M., Abliz, M., Fujiwara, N., ...
The results of magnetic susceptibility, electrical resistivity ($\rho$), heat-capacity (C) and thermopower (S) measurements on CeCuAs2, forming in ZrCuSi2-type tetragonal structure, are reported. Our...
Rayaprol, S., Sengupta, Kausik, Sampathkumaran, E. V., Matsushita, Y.
Heat-capacity (C) and ac susceptibility measurements have been performed on the spin-chain compounds, Sr3ZnRhO6 and Ca3NiMnO6, to establish their magnetic behavior and to explore whether there are...
Sampathkumaran, E. V., Fujiwara, N., Rayaprol, S., Madhu, P. K., Uwatoko, Y.
We have performed field-swept 59Co NMR measurements on the 'exotic' spin-chain material, Ca3Co2O6, crystallizing in K4CdCl6-type rhombohedral structure, believed to exhibit two magnetic transition...
Sengupta, Kausik, Rayaprol, S., Sampathkumaran, E. V., Doert, Th., Jemetio, J. P. F.
The results of dc magnetization, heat capacity, electrical resistivity (rho) and magnetoresistance measurements are reported in detail for the compounds, RCuAs2 for R= Pr, Nd, Sm, Gd, Tb, Dy, Ho, and...
Structural and magnetic anomalies among the spin-chain compounds, Ca3Co1+xIr1-xO6 (2003)
Rayaprol, S., Sengupta, Kausik, Sampathkumaran, E. V.
The results of x-ray diffraction, and ac and dc magnetization as a function of temperature are reported for a new class of spin-chain oxides, Ca3Co1+xIr1-xO6. While the x= 0.0, 0.3, 0.5 and 1.0 are...
Magnetic ordering, Kondo effect and superconductivity in Ce2-x(La, Y)xRhSi3 (2003)
Sengupta, Kausik, Rayaprol, S., Sampathkumaran, E. V.
The influence of positive and negative chemical pressure on the magnetic behavior of the compound, Ce2RhSi3, crystallizing in a AlB2-derived hexagonal structure and ordering antiferromagnetically...
Spin glass anomalies in stoichiometric spin-chain oxides, Ca3CoXO6 (X = Rh, Ir and Co) (2003)
Rayaprol, S., Sengupta, Kausik, Sampathkumaran, E. V.
The results of ac susceptibility (chi) measurements for Ca3CoXO6 (X = Rh, Ir and Co) compounds, containing spin-chains separated by Ca ions, are presented. All these compounds exhibit an unusually...
Evidence for the coexistence of low-dimensional magnetism and long-range order in Ca3CoRhO6 (2003)
Loewenhaupt, M., Schaefer, W., Niazi, A., Sampathkumaran, E. V.
We report the results of neutron powder diffraction studies on the spin-chain compound Ca3CoRhO6 in the temperature range 3 to 293 K. Bragg peaks due to magnetic ordering start appearing below about...
Magnetic behaviour of quasi-one-dimensional oxides, Ca$_3$Co$_(1+x)$Mn$_{1-x}$O$_6$ (2003)
Rayaprol, S., Sengupta, Kausik, Sampathkumaran, E. V.
The results of ac and dc magnetization and heat capacity measurements on the oxides, Ca$_3$Co$_{1+x}$Mn$_{1-x}$O$_6$, forming in a K$_4$CdCl$_6$-derived rhombohedral quasi-one-dimensional crystal...
Sampathkumaran, E. V., Sengupta, Kausik, Rayaprol, S., Iyer, Kartik K., Doert, Th., Jemetio, J. P. F.
We report an unusual temperature (T) dependent electrical resistivity($\rho$) behavior in a class of ternary intermetallic compounds of the type RCuAs$_2$ (R= Rare-earths). For some rare-earths (Sm,...
Sengupta, Kausik, Rayaprol, S., Iyer, K. K., Sampathkumaran, E. V.
The results of ac and dc magnetization and heat capacity measurements as a function of temperature (T = 1.8 to 300 K) are reported for a quasi-one-dimensional compound, Ca$_3$CuMnO$_6$, crystallizing...
Magnetic frustration in a stoichiometric spin-chain compound, Ca$_3$CoIrO$_6$ (2003)
Rayaprol, S., Sengupta, Kausik, Sampathkumaran, E. V.
The temperature dependent ac and dc magnetization and heat capacity data of Ca$_3$CoIrO$_6$, a spin-chain compound crystallizing in a K$_4$CdCl$_6$-derived rhombohedral structure, show the features...
Paulose, P. L., Sampathkumaran, E. V., Bitterlich, H., Behr, G., Loser, W.
We report temperature dependent ac susceptibility ($\chi$) measurements on a high quality single crystal of Tb$_2$PdSi$_3$, crystallizing in a AlB$_2$-derived hexagonal structure. This compound is...
Do we understand electron correlation effects in Gadolinium based intermetallic compounds? (2002)
Sampathkumaran, E. V., Mallik, R.
Recognising the difficulties in systematic understanding of the physical characteristics of strongly correlated f-electron systems, we considered it worthwhile to subject the so-called "normal"...
ESR investigation of the spin dynamics in (Gd_{1-x}Y_{x})_2PdSi_{3} (2002)
Deisenhofer, J., Loidl, A., Sampathkumaran, E. V.
We report electron-spin resonance measurements in polycrystalline samples of (Gd_{1-x}Y_{x})_2PdSi_{3}. We observe the onset of a broadening of the linewidth and of a decrease of the resonance field...
Interesting thermomagnetic history effects in the antiferromagnetic state of SmMn_2Ge_2 (2002)
Roy, S. B., Chaudhary, S., Chattopadhyay, M. K., Chaddah, P., Sampathkumaran, E. V.
We present results of magnetization measurements showing that the magnetic response of the antiferromagnetic state of SmMn_2Ge_2 depends on the path used in the field(H)-temperature(T) phase space to...
Ac susceptibility behaviour of Ce_2Pd_{1-x}Co_{x}Si_3 (2002)
We report the results of ac susceptibility chi measurements for various compositions of the series, Ce_2Pd_{1-x}Co_xSi_3, in the polycrystalline form, which has been previously reported to undergo a...
Magnetic behavior of single crystalline Ho$_2$PdSi$_3$ (2002)
Sampathkumaran, E. V., Bitterlich, H., Iyer, K. K., Löser, W., Behr, G.
The magnetic behavior of single-crystal Ho$_2$PdSi$_3$, crystallizing in an AlB$_2$-derived hexagonal structure, is investigated by magnetic susceptibility ($\chi$) and electrical resistivity...
Thermomagnetic history effects in SmMn$_2$Ge$_2$ (2002)
Chaudhary, Sujeet, Chattopadhyay, M. K., Singh, Kanwal Jeet, Roy, S. B., Chaddah, P., Sampathkumaran, E. V.
The intermetallic compound SmMn$_2$Ge$_2$, displaying multiple magnetic phase transitions, is being investigated in detail for its magnetization behavior near the 145 K first order ferromagnetic to...
Majumdar, Subham, Sampathkumaran, E. V., Berger, St., Della Mea, M., Michor, H., Bauer, E., ...
We report the results of magnetic measurements for the solid solution Ce$_2$Au$_{1-x}$Co$_x$Si$_3$. The results reveal that this solid solution is characterized by a magnetic phase diagram (plot of...
Sampathkumaran, E. V., Niazi, Asad
We report the results of dc and ac magnetization measurements as a function of temperature (1.8 - 300 K) for the spin chain compound, Ca$_3$CoRhO$_6$, which has been recently reported to exhibit a...
Niazi, Asad, Paulose, P. L., Sampathkumaran, E. V.
The single crystalline form of an insulator, Sr$_3$CuIrO$_{6+\delta}$, is shown to exhibit unexpectedly more than one magnetic transition (at 5 and 19 K) with spin-glass-like magnetic susceptibility...
Crossover in the nature of the metallic phases in the perovskite-type RNiO_3 (2002)
Okazaki, K., Mizokawa, T., Fujimori, A., Sampathkumaran, E. V., Martinez-Lope, M. J., Alonso, J. A.
We have measured the photoemission spectra of Nd$_{1-x}$Sm$_{x}$NiO$_{3}$, where the metal-insulator transition and the N\'{e}el ordering occur at the same temperature for $x \lesssim 0.4$ and the...
Magnetic anomalies in the spin chain system, Sr$_3$Cu$_{1-x}$Zn$_x$IrO$_6$ (2001)
Niazi, Asad, Sampathkumaran, E. V., Paulose, P. L., Eckert, D., Handstein, A.
We report the results of ac and dc magnetization (M) and heat-capacity (C) measurements on the solid solution, Sr$_3$Cu$_{1-x}$Zn$_x$IrO$_6$. While the Zn end member is known to form in a...
Niazi, Asad, Sampathkumaran, E. V., Paulose, P. L., Eckert, D., Handstein, A.
Ac and dc magnetization and heat-capacity (C) measurements performed on the pseudo-one-dimensional compound Sr$_3$CuIrO$_6$ reveal a competition between antiferromagnetic (AF) and ferromagnetic (F)...
Observation of superconductivity in Y$_2$PdGe$_3$, structurally same as MgB$_2$ (2001)
Sampathkumaran, E. V., Majumdar, Subham
The results of electrical resistance (1.4 - 300 K), magnetization (2-300 K) and heat-capacity (2 - 50 K) measurements in Y$_2$PdGe$_3$, found to crystallize in a AlB$_2$-derived hexagonalstructure,...
Saha, S. R., Sugawara, H., Matsuda, T. D., Aoki, Y., Sato, H., Sampathkumaran, E. V.
Magnetization, heat capacity, electrical resistivity, thermoelectric power, and Hall effect have been investigated on single-crystalline Ce_2PdSi_3. This compound is shown to order...
Kumar, M. Mahesh, Sampathkumaran, E. V.
We have investigated the magnetic and electrical resistance behaviour of Ca$_{3-x}$Y$_x$LiRuO$_6$. The parent compound exhibits magnetic ordering from Ru sublattice at a rather high temperature, 113...
Magnetoresistance in ordered and disordered double perovskite oxide, Sr$_2$FeMoO$_6$ (2000)
Sarma, D. D., Sampathkumaran, E. V., Ray, Sugata, Nagarajan, R., Majumdar, Subham, Kumar, Ashwani, ...
We have prepared crystallographically ordered and disorder specimens of the double perovskite, Sr$_2$FeMoO$_6$ and investigated their magnetoresistance behaviour. The extent of ordering between the...
Sampathkumaran, E. V., Mallik, R., Paulose, P. L., Majumdar, Subham
A closer look at the temperature (T) dependence of magnetoresistance (MR) of two polycrystalline magnetic compounds, LaMn$_2$Ge$_2$ and SmMn$_2$Ge$_2$, previously reported by us, is made. A common...
Saha, S. R., Sugawara, H., Matsuda, T. D., Sato, H., Mallik, R., Sampathkumaran, E. V.
Electrical resistivity ($\rho$), magnetoresistance (MR), magnetization, thermopower and Hall effect measurements on the single crystal Gd$_{2}$PdSi$_3$, crystallizing in an AlB$_2$-derived hexagonal...
Magnetic behaviour of Eu_2CuSi_3: Large negative magnetoresistance above Curie temperature (1999)
Majumdar, Subham, Mallik, R., Sampathkumaran, E. V., Rupprecht, Kirsten, Wortmann, G.
We report here the results of magnetic susceptibility, electrical-resistivity, magnetoresistance (MR), heat-capacity and ^{151}Eu Mossbauer effect measurements on the compound, Eu_2CuSi_3,...
Majumdar, Subham, Kumar, M. Mahesh, Mallik, R., Sampathkumaran, E. V.
The results of electrical resistivity, heat capacity and magnetic susceptibility behavior of new class of alloys, Ce_{2-x}La_{x}CoSi_{3}, are reported. The x= 0.0 alloy is mixed valent and La...
Magnetic precursor effects in Gd alloys (1998)
Mallik, R., Sampathkumaran, E. V.
The behaviour of electrical resistivity ($\rho$) and magnetoresistance in the vicinity of respective magnetic ordering temperatures in a number of Gd alloys is reported. In some compounds, e.g.,...
Mallik, R., Sampathkumaran, E. V., Paulose, P. L., Nagarajan, V.
The results of magnetoresistance ($\Delta \rho /\rho$)measurements in GdNi, in the temperature range 4.2 to 300 K are reported. The sign of $\Delta \rho /\rho $ above the Curie temperature (Tc= 70 K)...
Majumdar, S., Mallik, R., Sampathkumaran, E. V., Paulose, P. L.
Results of low temperature magnetoresistance ($\Delta\rho/\rho$) and isothermal magnetization (M) measurements on polycrystalline ferromagnetic (T_C close to 300 K) natural multilayers,...
Mallik, R., Sampathkumaran, E. V., Paulose, P. L.
The results of heat-capacity, magnetic susceptibility, electrical resistivity and magnetoresistance $(\Delta \rho/\rho)$ measurements on the compounds Tb$_2$PdSi$_3$ and Dy$_2$PdSi$_3$, are reported....