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The evolution of magnetic polarons in Sr doped LaCoO3 (La1-xSrxCoO3) single crystal and polycrystalline samples are investigated by employing dc and ac magnetic measurement and small angle neutron scattering (SANS) techniques. The effect of magnetic field and temperature on magnetic polarons is experimentally studied for La0.875Sr0.125CoO3 and La0.85Sr0.15CoO3 compounds that belong to the spin glass insulating regime of the broader compositional phase diagram of this system. Langevin analyses of the isothermal magnetization curves in the notional paramagnetic regime prove the existence of magnetic polarons with large moments. The dc field superimposed ac susceptibility data and the analysis of the glassy dynamics prove that the size of polarons in 15% Sr doped crystal increase as the field is increased while the field effect is not visible in the 12.5% Sr doped crystal. A polycrystalline sample of La0.85Sr0.15CoO3 is analyzed by SANS experiments, which confirm nonzero correlation length at temperatures far above the macroscopic ordering temperature and hence the presence of magnetic polarons.

The evolution of magnetic polarons in Sr doped LaCoO3 (La1-xSrxCoO3) single crystal and polycrystalline samples are investigated by employing dc and ac magnetic measurement and small angle neutron scattering (SANS) techniques. The effect of magnetic field and temperature on magnetic polarons is experimentally studied for La0.875Sr0.125CoO3 and La0.85Sr0.15CoO3 compounds that belong to the spin glass insulating regime of the broader compositional phase diagram of this system. Langevin analyses of the isothermal magnetization curves in the notional paramagnetic regime prove the existence of magnetic polarons with large moments. The dc field superimposed ac susceptibility data and the analysis of the glassy dynamics prove that the size of polarons in 15% Sr doped crystal increase as the field is increased while the field effect is not visible in the 12.5% Sr doped crystal. A polycrystalline sample of La0.85Sr0.15CoO3 is analyzed by SANS experiments, which confirm nonzero correlation length at temperatures far above the macroscopic ordering temperature and hence the presence of magnetic polarons.

The evolution of magnetic polarons in Sr doped LaCoO3 (La1-xSrxCoO3) single crystal and polycrystalline samples are investigated by employing dc and ac magnetic measurement and small angle neutron scattering (SANS) techniques. The effect of magnetic field and temperature on magnetic polarons is experimentally studied for La0.875Sr0.125CoO3 and La0.85Sr0.15CoO3 compounds that belong to the spin glass insulating regime of the broader compositional phase diagram of this system. Langevin analyses of the isothermal magnetization curves in the notional paramagnetic regime prove the existence of magnetic polarons with large moments. The dc field superimposed ac susceptibility data and the analysis of the glassy dynamics prove that the size of polarons in 15% Sr doped crystal increase as the field is increased while the field effect is not visible in the 12.5% Sr doped crystal. A polycrystalline sample of La0.85Sr0.15CoO3 is analyzed by SANS experiments, which confirm nonzero correlation length at temperatures far above the macroscopic ordering temperature and hence the presence of magnetic polarons.

The evolution of magnetic polarons in Sr doped LaCoO3 (La1-xSrxCoO3) single crystal and polycrystalline samples are investigated by employing dc and ac magnetic measurement and small angle neutron scattering (SANS) techniques. The effect of magnetic field and temperature on magnetic polarons is experimentally studied for La0.875Sr0.125CoO3 and La0.85Sr0.15CoO3 compounds that belong to the spin glass insulating regime of the broader compositional phase diagram of this system. Langevin analyses of the isothermal magnetization curves in the notional paramagnetic regime prove the existence of magnetic polarons with large moments. The dc field superimposed ac susceptibility data and the analysis of the glassy dynamics prove that the size of polarons in 15% Sr doped crystal increase as the field is increased while the field effect is not visible in the 12.5% Sr doped crystal. A polycrystalline sample of La0.85Sr0.15CoO3 is analyzed by SANS experiments, which confirm nonzero correlation length at temperatures far above the macroscopic ordering temperature and hence the presence of magnetic polarons.

The evolution of magnetic polarons in Sr doped LaCoO3 (La1-xSrxCoO3) single crystal and polycrystalline samples are investigated by employing dc and ac magnetic measurement and small angle neutron scattering (SANS) techniques. The effect of magnetic field and temperature on magnetic polarons is experimentally studied for La0.875Sr0.125CoO3 and La0.85Sr0.15CoO3 compounds that belong to the spin glass insulating regime of the broader compositional phase diagram of this system. Langevin analyses of the isothermal magnetization curves in the notional paramagnetic regime prove the existence of magnetic polarons with large moments. The dc field superimposed ac susceptibility data and the analysis of the glassy dynamics prove that the size of polarons in 15% Sr doped crystal increase as the field is increased while the field effect is not visible in the 12.5% Sr doped crystal. A polycrystalline sample of La0.85Sr0.15CoO3 is analyzed by SANS experiments, which confirm nonzero correlation length at temperatures far above the macroscopic ordering temperature and hence the presence of magnetic polarons.

The magnetic ground states in highly ordered double perovskites LaSr1-xCaxNiReO6 (x = 0.0, 0.5, 1.0) are studied in view of the Goodenough-Kanamori rules of superexchange interactions in this paper. In LaSrNiReO6, Ni and Re sublattices are found to exhibit curious magnetic states separately, but no long range magnetic ordering is achieved. The magnetic transition at similar to 255 K is identified with the independent Re sublattice magnetic ordering. Interestingly, the sublattice interactions are tuned by modifying the Ni-O-Re bond angles through Ca doping. Upon Ca doping, the Ni and Re sublattices start to display a ferrimagnetically ordered state at low temperature. The neutron powder diffraction data reveals long range ferrimagnetic ordering of the Ni and Re magnetic sublattices along the crystallographic b-axis. The transition temperature of the ferrimagnetic phase increases monotonically with increasing Ca concentration.

The magnetic ground states in highly ordered double perovskites LaSr1-xCaxNiReO6 (x = 0.0, 0.5, 1.0) are studied in view of the Goodenough-Kanamori rules of superexchange interactions in this paper. In LaSrNiReO6, Ni and Re sublattices are found to exhibit curious magnetic states separately, but no long range magnetic ordering is achieved. The magnetic transition at similar to 255 K is identified with the independent Re sublattice magnetic ordering. Interestingly, the sublattice interactions are tuned by modifying the Ni-O-Re bond angles through Ca doping. Upon Ca doping, the Ni and Re sublattices start to display a ferrimagnetically ordered state at low temperature. The neutron powder diffraction data reveals long range ferrimagnetic ordering of the Ni and Re magnetic sublattices along the crystallographic b-axis. The transition temperature of the ferrimagnetic phase increases monotonically with increasing Ca concentration., QC 20200108

The magnetic ground states in highly ordered double perovskites LaSr1-xCaxNiReO6 (x = 0.0, 0.5, 1.0) are studied in view of the Goodenough-Kanamori rules of superexchange interactions in this paper. In LaSrNiReO6, Ni and Re sublattices are found to exhibit curious magnetic states separately, but no long range magnetic ordering is achieved. The magnetic transition at similar to 255 K is identified with the independent Re sublattice magnetic ordering. Interestingly, the sublattice interactions are tuned by modifying the Ni-O-Re bond angles through Ca doping. Upon Ca doping, the Ni and Re sublattices start to display a ferrimagnetically ordered state at low temperature. The neutron powder diffraction data reveals long range ferrimagnetic ordering of the Ni and Re magnetic sublattices along the crystallographic b-axis. The transition temperature of the ferrimagnetic phase increases monotonically with increasing Ca concentration.

The magnetic ground states in highly ordered double perovskites LaSr1-xCaxNiReO6 (x = 0.0, 0.5, 1.0) are studied in view of the Goodenough-Kanamori rules of superexchange interactions in this paper. In LaSrNiReO6, Ni and Re sublattices are found to exhibit curious magnetic states separately, but no long range magnetic ordering is achieved. The magnetic transition at similar to 255 K is identified with the independent Re sublattice magnetic ordering. Interestingly, the sublattice interactions are tuned by modifying the Ni-O-Re bond angles through Ca doping. Upon Ca doping, the Ni and Re sublattices start to display a ferrimagnetically ordered state at low temperature. The neutron powder diffraction data reveals long range ferrimagnetic ordering of the Ni and Re magnetic sublattices along the crystallographic b-axis. The transition temperature of the ferrimagnetic phase increases monotonically with increasing Ca concentration.

The magnetic ground states in highly ordered double perovskites LaSr1-xCaxNiReO6 (x = 0.0, 0.5, 1.0) are studied in view of the Goodenough-Kanamori rules of superexchange interactions in this paper. In LaSrNiReO6, Ni and Re sublattices are found to exhibit curious magnetic states separately, but no long range magnetic ordering is achieved. The magnetic transition at similar to 255 K is identified with the independent Re sublattice magnetic ordering. Interestingly, the sublattice interactions are tuned by modifying the Ni-O-Re bond angles through Ca doping. Upon Ca doping, the Ni and Re sublattices start to display a ferrimagnetically ordered state at low temperature. The neutron powder diffraction data reveals long range ferrimagnetic ordering of the Ni and Re magnetic sublattices along the crystallographic b-axis. The transition temperature of the ferrimagnetic phase increases monotonically with increasing Ca concentration.

The magnetic ground states in highly ordered double perovskites LaSr1-xCaxNiReO6 (x = 0.0, 0.5, 1.0) are studied in view of the Goodenough-Kanamori rules of superexchange interactions in this paper. In LaSrNiReO6, Ni and Re sublattices are found to exhibit curious magnetic states separately, but no long range magnetic ordering is achieved. The magnetic transition at similar to 255 K is identified with the independent Re sublattice magnetic ordering. Interestingly, the sublattice interactions are tuned by modifying the Ni-O-Re bond angles through Ca doping. Upon Ca doping, the Ni and Re sublattices start to display a ferrimagnetically ordered state at low temperature. The neutron powder diffraction data reveals long range ferrimagnetic ordering of the Ni and Re magnetic sublattices along the crystallographic b-axis. The transition temperature of the ferrimagnetic phase increases monotonically with increasing Ca concentration.

Examining the visual tactics of framing flowing water in landscape painting and riparian architecture in Braj, a pilgrimage centre in North India where the god Krishna is believed to have spent his youth, the essay foregrounds a new conception of hydroaesthetics that emerged with the onset of the Little Ice Age (c. 1550–1850), a climatic period marked by catastrophic droughts and famines in South Asia. An engagement with the hydroaesthetics of beholding the river Yamuna's passage through Braj, the essay argues, brings to the forefront a reciprocal relationship between artistic practices based on a theological aesthetic of venerating the natural environment and ecological calamities. In doing so, the essay attempts to delineate a possible methodology for an ecological art history.

Locating the genealogies of postcolonialism in 20th-century anti-colonial thinking, the entry delineates an array of intellectual practices that have coalesced around the sign of this concept-term. Along with outlining some of the key theoretical frameworks that have engendered postcolonial thought, the essay also pays attention to creative texts such as contemporary performance art to chart a tentative history and historiography of postcolonial theory and praxis.

Examining the visual tactics of framing flowing water in landscape painting and riparian architecture in Braj, a pilgrimage centre in North India where the god Krishna is believed to have spent his youth, the essay foregrounds a new conception of hydroaesthetics that emerged with the onset of the Little Ice Age (c. 1550–1850), a climatic period marked by catastrophic droughts and famines in South Asia. An engagement with the hydroaesthetics of beholding the river Yamuna's passage through Braj, the essay argues, brings to the forefront a reciprocal relationship between artistic practices based on a theological aesthetic of venerating the natural environment and ecological calamities. In doing so, the essay attempts to delineate a possible methodology for an ecological art history.

Locating the genealogies of postcolonialism in 20th-century anti-colonial thinking, the entry delineates an array of intellectual practices that have coalesced around the sign of this concept-term. Along with outlining some of the key theoretical frameworks that have engendered postcolonial thought, the essay also pays attention to creative texts such as contemporary performance art to chart a tentative history and historiography of postcolonial theory and praxis.

© Association of Art Historians 2015. Internalizing colonial accusations of the effeminacy of the native male body, nineteenth-century Indian ideologues and reformers attempted to redeem the national body through a range of phallocentric body cultures. Anti-colonial art history, however, deliberately appropriated colonizing discourses of the effeminate native body to epistemologically challenge the hegemonic hyper-masculinity advocated by both the regulatory mechanisms of the British empire and a larger nationalist body culture in colonial India. The ingenious invention of a discursive intimacy between yoga and an aesthetics of demasculinization led to the strategic resignification of the male body in early Indian sculpture as both a sign and the site of an imagined national life. Through a close analysis of art writing and photography, art pedagogy and colonial archaeology, visual practices and sartorial cultures, the essay delineates the fin-de-siècle politics and aesthetics of demasculinization that had led to the establishment of anti-colonial Indian art historys disciplinary and methodological concerns.

© Association of Art Historians 2015. Internalizing colonial accusations of the effeminacy of the native male body, nineteenth-century Indian ideologues and reformers attempted to redeem the national body through a range of phallocentric body cultures. Anti-colonial art history, however, deliberately appropriated colonizing discourses of the effeminate native body to epistemologically challenge the hegemonic hyper-masculinity advocated by both the regulatory mechanisms of the British empire and a larger nationalist body culture in colonial India. The ingenious invention of a discursive intimacy between yoga and an aesthetics of demasculinization led to the strategic resignification of the male body in early Indian sculpture as both a sign and the site of an imagined national life. Through a close analysis of art writing and photography, art pedagogy and colonial archaeology, visual practices and sartorial cultures, the essay delineates the fin-de-siècle politics and aesthetics of demasculinization that had led to the establishment of anti-colonial Indian art historys disciplinary and methodological concerns.

Spin-orbit coupling (SOC) is found to be crucial for understanding themagnetic and electronic properties of 5d transitionmetal oxides. In 5d systems, with Ir5+ ions, where ideally a nonmagnetic J = 0 ground state is expected to be stabilized in the presence of strong SOC, often spontaneous moments are generated due to hopping induced superexchange. This effect is more pronounced when the Ir atoms are close by, as in systems with Ir2O9 dimers in 6H Ba3MIr2O9 compounds where magnetism is an outcome of complex Ir-O-Ir exchange paths, and is strongly influenced by the presence of local distortions. We find that subtle variations in the local structure of Ba3MIr2O9 (M = Mg, Sr, and Ca) lead to markedly differentmagnetic properties. While SOC plays a pivotal role in explaining the insulating ground states of these systems, it is seen that Ba3MgIr2O9, having a P6(3)/mmc symmetry, does not order down to low temperature despite having antiferromagnetic exchange interactions, while Ba3CaIr2O9 shows weak dimer-like features and stabilizes in C2/c' magnetic configuration with no net moment, and Ba3SrIr2O9 possesses a ground state corresponding to themagnetic space groupC2'/c' and exhibits ferromagnet-like features.

From its establishment in 1887, the Jaipur Museum was a locus of contestation between its principal patron, the Indian state of Jaipur, and the British government. The examination of narratives of contestation alongside the museum's architecture and display reveals a localized nineteenth-century museological practice that strategically operated from within the bureaucracies of colonial governance, yet destabilized the imperial aspirations of colonial museology. While museums as instruments of modern knowledge making have been seen by scholars as a failure, “native” participation in the nineteenth-century exhibitionary order can also be read as an indigenous reframing of modern museology in the colony.

From its establishment in 1887, the Jaipur Museum was a locus of contestation between its principal patron, the Indian state of Jaipur, and the British government. The examination of narratives of contestation alongside the museum's architecture and display reveals a localized nineteenth-century museological practice that strategically operated from within the bureaucracies of colonial governance, yet destabilized the imperial aspirations of colonial museology. While museums as instruments of modern knowledge making have been seen by scholars as a failure, “native” participation in the nineteenth-century exhibitionary order can also be read as an indigenous reframing of modern museology in the colony.

This is the third volume in The Art Seminar, James Elkin's series of conversations on art and visual studies. Is Art History Global? stages an international conversation among art historians and critics on the subject of the practice and responsibility of global thinking within the discipline.

This is the third volume in The Art Seminar, James Elkin's series of conversations on art and visual studies. Is Art History Global? stages an international conversation among art historians and critics on the subject of the practice and responsibility of global thinking within the discipline.

This is the third volume in The Art Seminar, James Elkin's series of conversations on art and visual studies. Is Art History Global? stages an international conversation among art historians and critics on the subject of the practice and responsibility of global thinking within the discipline.

We show using detailed magnetic and thermodynamic studies and theoretical calculations that the ground state of Ba3ZnIr2O9 is a realization of a novel spin-orbital liquid state. Our results reveal that Ba3ZnIr2O9 with Ir5+ (5d(4)) ions and strong spin-orbit coupling (SOC) arrives very close to the elusive J = 0 state but each Ir ion still possesses a weak moment. Ab initio density functional calculations indicate that this moment is developed due to superexchange, mediated by a strong intradimer hopping mechanism. While the Ir spins within the structural Ir2O9 dimer are expected to form a spin-orbit singlet state (SOS) with no resultant moment, substantial frustration arising from interdimer exchange interactions induce quantum fluctuations in these possible SOS states favoring a spin-orbital liquid phase down to at least 100 mK., QC 20160406

We show using detailed magnetic and thermodynamic studies and theoretical calculations that the ground state of Ba3ZnIr2O9 is a realization of a novel spin-orbital liquid state. Our results reveal that Ba3ZnIr2O9 with Ir5+ (5d(4)) ions and strong spin-orbit coupling (SOC) arrives very close to the elusive J = 0 state but each Ir ion still possesses a weak moment. Ab initio density functional calculations indicate that this moment is developed due to superexchange, mediated by a strong intradimer hopping mechanism. While the Ir spins within the structural Ir2O9 dimer are expected to form a spin-orbit singlet state (SOS) with no resultant moment, substantial frustration arising from interdimer exchange interactions induce quantum fluctuations in these possible SOS states favoring a spin-orbital liquid phase down to at least 100 mK.

We examine the simultaneous management of hedge funds and funds of hedge funds. Hedge fund firms can choose to simultaneously offer a fund of hedge funds. Similarly, fund of hedge funds firms can simultaneously offer a hedge fund. We find that although superior past performance and larger size drive the decision to become simultaneous for hedge fund firms, past flows drive the decision for fund of hedge funds firms. The effects of simultaneity are also different. When hedge fund firms start funds of hedge funds, we find evidence of value creation, driven by better management of economies of scale and cross learning. In contrast, fund of hedge funds firms starting hedge funds destroy value due to expansion beyond core competencies and agency problems. We find that firms learn about their competencies in the two business lines and discontinue underperforming simultaneity arrangements to focus on the business where they perform better.

We examine the simultaneous management of hedge funds and funds of hedge funds. Hedge fund firms can choose to simultaneously offer a fund of hedge funds. Similarly, fund of hedge funds firms can simultaneously offer a hedge fund. We find that although superior past performance and larger size drive the decision to become simultaneous for hedge fund firms, past flows drive the decision for fund of hedge funds firms. The effects of simultaneity are also different. When hedge fund firms start funds of hedge funds, we find evidence of value creation, driven by better management of economies of scale and cross learning. In contrast, fund of hedge funds firms starting hedge funds destroy value due to expansion beyond core competencies and agency problems. We find that firms learn about their competencies in the two business lines and discontinue underperforming simultaneity arrangements to focus on the business where they perform better.

We report results of the magnetization and ac susceptibility measurements down to very low fields on a single crystal of the perovskite manganite, La-0.82 Ca-0.18 MnO3. This composition falls in the intriguing ferromagnetic insulator region of the manganite phase diagram. In contrast to earlier beliefs, our investigations reveal that magnetically (and in every other sense), this is a single- phase system with a ferromagnetic ordering temperature of around 170 K. However, this ferromagnetic state is magnetically frustrated, and the system exhibits pronounced glassy dynamics below 90 K. Based on measured dynamical properties, we propose that this quasi-long-ranged ferromagnetic phase, and the associated superspin glass behavior, is the true magnetic state of the system, rather than being a macroscopic mixture of ferromagnetic and antiferromagnetic phases, as often suggested. Our results provide an understanding of the quantum phase transition from an antiferromagnetic insulator to a ferromagnetic metal via this ferromagnetic state as a function of x in La1-xCaxMnO3, in terms of the possible formation of magnetic polarons.

Nearly monodisperse spherical magnetite (Fe3O4) nanoparticles are prepared by colloidal chemistry route. Magnetic and electronic transport properties of the annealed pellets of these nanoparticles are reported. Effect of external magnetic and electric fields on the magnetic and transport properties of the material are studied as a function of temperature. We find that the highest resistance state of the ferromagnetic system occurs at a magnetic field which is approximately equal to its magnetic coercivity; this establishes the magnetoresistance (MR) in this system to be of the conventional tunnelling type MR as against the spin-valve type MR found more recently in some ferromagnetic oxide systems. The material also shows electroresistance (ER) property with its low-temperature resistance being strongly dependent on the excitation current that is used for the measurement. This ER effect is concluded to be intrinsic to the material and is attributed to the electric field-induced melting of the charge-order state in magnetite., Correction in: Journal of Experimental Nanoscience, 2014, Volume 9, Issue 7, pp. 762, DOI: 10.1080/17458080.2012.699222

We report results of the magnetization and ac susceptibility measurements down to very low fields on a single crystal of the perovskite manganite, La-0.82 Ca-0.18 MnO3. This composition falls in the intriguing ferromagnetic insulator region of the manganite phase diagram. In contrast to earlier beliefs, our investigations reveal that magnetically (and in every other sense), this is a single- phase system with a ferromagnetic ordering temperature of around 170 K. However, this ferromagnetic state is magnetically frustrated, and the system exhibits pronounced glassy dynamics below 90 K. Based on measured dynamical properties, we propose that this quasi-long-ranged ferromagnetic phase, and the associated superspin glass behavior, is the true magnetic state of the system, rather than being a macroscopic mixture of ferromagnetic and antiferromagnetic phases, as often suggested. Our results provide an understanding of the quantum phase transition from an antiferromagnetic insulator to a ferromagnetic metal via this ferromagnetic state as a function of x in La1-xCaxMnO3, in terms of the possible formation of magnetic polarons.

We report results of the magnetization and ac susceptibility measurements down to very low fields on a single crystal of the perovskite manganite, La-0.82 Ca-0.18 MnO3. This composition falls in the intriguing ferromagnetic insulator region of the manganite phase diagram. In contrast to earlier beliefs, our investigations reveal that magnetically (and in every other sense), this is a single- phase system with a ferromagnetic ordering temperature of around 170 K. However, this ferromagnetic state is magnetically frustrated, and the system exhibits pronounced glassy dynamics below 90 K. Based on measured dynamical properties, we propose that this quasi-long-ranged ferromagnetic phase, and the associated superspin glass behavior, is the true magnetic state of the system, rather than being a macroscopic mixture of ferromagnetic and antiferromagnetic phases, as often suggested. Our results provide an understanding of the quantum phase transition from an antiferromagnetic insulator to a ferromagnetic metal via this ferromagnetic state as a function of x in La1-xCaxMnO3, in terms of the possible formation of magnetic polarons.

We report results of the magnetization and ac susceptibility measurements down to very low fields on a single crystal of the perovskite manganite, La-0.82 Ca-0.18 MnO3. This composition falls in the intriguing ferromagnetic insulator region of the manganite phase diagram. In contrast to earlier beliefs, our investigations reveal that magnetically (and in every other sense), this is a single- phase system with a ferromagnetic ordering temperature of around 170 K. However, this ferromagnetic state is magnetically frustrated, and the system exhibits pronounced glassy dynamics below 90 K. Based on measured dynamical properties, we propose that this quasi-long-ranged ferromagnetic phase, and the associated superspin glass behavior, is the true magnetic state of the system, rather than being a macroscopic mixture of ferromagnetic and antiferromagnetic phases, as often suggested. Our results provide an understanding of the quantum phase transition from an antiferromagnetic insulator to a ferromagnetic metal via this ferromagnetic state as a function of x in La1-xCaxMnO3, in terms of the possible formation of magnetic polarons.

We report results of the magnetization and ac susceptibility measurements down to very low fields on a single crystal of the perovskite manganite, La-0.82 Ca-0.18 MnO3. This composition falls in the intriguing ferromagnetic insulator region of the manganite phase diagram. In contrast to earlier beliefs, our investigations reveal that magnetically (and in every other sense), this is a single- phase system with a ferromagnetic ordering temperature of around 170 K. However, this ferromagnetic state is magnetically frustrated, and the system exhibits pronounced glassy dynamics below 90 K. Based on measured dynamical properties, we propose that this quasi-long-ranged ferromagnetic phase, and the associated superspin glass behavior, is the true magnetic state of the system, rather than being a macroscopic mixture of ferromagnetic and antiferromagnetic phases, as often suggested. Our results provide an understanding of the quantum phase transition from an antiferromagnetic insulator to a ferromagnetic metal via this ferromagnetic state as a function of x in La1-xCaxMnO3, in terms of the possible formation of magnetic polarons.

Naturally occurring spin-valve-type magnetoresistance (SVMR), recently observed in Sr2FeMoO6 samples, suggests the possibility of decoupling the maximal resistance from the coercivity of the sample. Here we present the evidence that SVMR can be engineered in specifically designed and fabricated core-shell nanoparticle systems, realized here in terms of soft magnetic Fe3O4 as the core and hard magnetic insulator CoFe2O4 as the shell materials. We show that this provides a magnetically switchable tunnel barrier that controls the magnetoresistance of the system, instead of the magnetic properties of the magnetic grain material, Fe3O4, and thus establishing the feasibility of engineered SVMR structures.

Sr2FeMoO6 is a well-known double perovskite with exciting high-temperature magnetic properties. Through various magnetic and spectroscopic measurements, we collect compelling evidence here that this compound can be driven into a rare three-dimensional antiferromagnetic metallic state by heavy electron doping (70% Sr2+ substitution by La3+). Moreover, local structural study of these Sr2-xLaxFeMoO6 (1.0 <= x <= 1.5) compounds reveals unusual atomic scale phase distribution in terms of La,Fe- and Sr,Mo-rich regions driven by strong La-O covalency, a phenomenon hitherto undisclosed in double perovskites. The general trend of our findings is in agreement with theoretical calculations carried out on realistic structures having local chemical fluctuations, which reconfirms the relevance of the kinetic-energy-driven magnetic model.

An unusual atomic scale chemical fluctuation in LaSrVMoO6, in terms of narrow patches of La, V and Sr,Mo-rich phases, has been probed in detail to understand the origin of such a chemical state. Exhaustive tuning of the equilibrium synthesis parameters showed that the extent of phase separation can never be melted down below a unit cell dimension making it impossible to achieve the conventional B-site ordered structure, which establishes that the observed "inhomogeneous" patchlike structure with minimum dimension of few angstroms is a reality in LaSrVMoO6. Therefore another type of local chemical order, hitherto unknown in double perovskites, gets introduced here. X-ray diffraction, electron microscopy elemental mapping, magnetic, and various spectroscopic studies have been carried out on samples, synthesized under different conditions. These experimental results in conjunction with ab initio electronic structure calculation revealed that it is the energy stability, gained by typical La-O covalency as in LaVO3, that leads to the preferential La, V and Sr,Mo ionic proximity, and the consequent patchy structure.

Half-metallic antiferromagnets (HMAFMs) have been proposed theoretically long ago but have not been realized experimentally yet. Recently, a double perovskite compound, LaSrVMoO6, has been claimed to be an almost real HMAFM system. Here, we report detailed experimental and theoretical studies on this compound. Our results reveal that the compound is neither a half-metal nor an ordered antiferromagnet. Most importantly, an unusual chemical fluctuation is observed locally, which finally accounts for all the electronic and magnetic properties of this compound.

The dissertation consists of three chapters examining topics in corporate finance. In the first chapter, my co-author and I examine the efficiency gains from asset acquisitions. We propose a test that focuses specifically on whether anticipated synergies vary with a characteristic. We argue that the magnitude of the relationship between relative value and acquirer returns measures the degree of synergies associated with a particular set of acquisitions. We find that asset purchases generate positive synergies whereas mergers do not; mergers with private targets have positive synergies while mergers with public targets have negative synergies; and asset purchases by firms with better governance generate higher synergies. In the second chapter, I propose a model of IPO discounts with an issuer facing costs and benefits from an IPO that are proportional to issuer market capitalization. Oligopolistic IPO underwriters extract a fraction of the net benefits, generating the observed negative relationship between IPO underpricing and fraction of the firm sold during the IPO. I derive explicit empirical implications in terms of changes in this relationship arising from these factors. Tests of empirical predictions on data demonstrate consistency with the proposed model. Also consistent with the model, the fraction of the firm sold during the IPO is significantly different depending on these three factors. In the third chapter, my co-author and I study a contract in which management fees, incentive fees and a high water mark (HWM) provision drive a fund manager's effort and risk choices as well as the investor's walkaway decision. We model this relationship and calibrate the model to observed data. The model yields empirical predictions regarding the effect of a fund's distance from the HWM on effort, risk and walkaway behavior. Testing the model on empirical data, we find that as funds fall from the HWM, future expected returns fall, the incidence of fund closure increases a