Heat capacity and magnetoresistance in Dy(Co,Si)2 compounds

Magnetocaloric effect and magnetoresistance have been studied in Dy(Co1-xSix)2 [x=0, 0.075 and 0.15] compounds. Magnetocaloric effect has been calculated in terms of adiabatic temperatue change (Delta Tad) as well as isothermal magnetic entropy change (Delta SM) using the heat capacity data. The maximum values of DeltaSM and DeltaTad for DyCo2 are found to be 11.4 JKg-1K-1 and 5.4 K, respectively. Both DSM and DTad decrease with Si concentration, reaching a value of 5.4 JKg-1K-1 and 3 K, respectively for x=0.15. The maximum magnetoresistance is found to about 32% in DyCo2, which decreases with increase in Si. These variations are explained on the basis of itinerant electron metamagnetism occurring in these compounds.Comment: Total 8 pages of text and figure

Heat capacity and magnetocaloric effect in polycrystalline Gd1-xSmxMn2Si2

We report the magnetocaloric effect in terms of isothermal magnetic entropy change as well as adiabatic temperature change, calculated using the heat capacity data. Using the zero field heat capacity data, the magnetic contribution to the heat capacity has been estimated. The variations in the magnetocaloric behavior have been explained on the basis of the magnetic structure of these compounds. The refrigerant capacities have also been calculated for these compounds

Multiple magnetic transitions and magnetocaloric effect in Gd1-xSmxMn2Ge2 compounds

Magnetic and magnetocaloric properties of polycrystalline samples of Gd1-xSmxMn2Ge2 have been studied. All the compounds except GdMn2Ge2 show re-entrant ferromagnetic behavior. Multiple magnetic transitions observed in these compounds are explained on the basis of the temperature dependences of the exchange strengths of the rare earth and Mn sublattices. Magnetocaloric effect is found to be positive at the re-entrant ferromagnetic transition, whereas it is negative at the antiferro-ferromagnetic transition. In SmMn2Ge2, the magnetic entropy change associated with the re-entrant transition is found to decrease with field, which is attributed to the admixture effect of the crystal field levels. The isothermal magnetic entropy change is found to decrease with increase in Sm concentration.Comment:

A study of socio demographic condition of North eastern Bihar

The main objective of this paper is to study the socio-economic and demographic conditions of this flood-prone region of north-eastern Bihar based on the data taken from a primarily conducted sample survey entitled “Migration and Related Characteristics - a Case Study of North-Eastern Bihar” during October 2009 to June 2010. A total of 664 households have been surveyed from the flood affected area of north-eastern Bihar consisting 8 villages of three districts Bhagalpur, Katihar and Purnia. Bivariate analysis and suitable statistical techniques have been applied. Results show that the study area is still backward from the other part of the state as well as the country

Performance Review of Major Packages in Light of Data Exchange Capabilities in R Ecosystem

An efficient strategy for managing data (exchange and manipulation) is essential for organization to run its data operations. In current scenario, when open-source computation platforms are widely used. The strategy guideline is need of the hour. It makes data flow efficient and fast in an information system. The work focused on benchmarking data exchange activities between data (excel and flat files) and R under the light of major computational frameworks native R [6], readr [7] and data.table [8]. It was concluded that for reading and writing excel files readxl [11] and writexl [10] are most efficient frameworks while for working with flat files data.table become un-disputed leader for both import and export exercises. These frameworks have out-performed when compared to its competitive frameworks like writexl and openxlsx [9] for readxl and writexl. data.table” found superior than native R implementation and data.table. Organization can consider these findings as guidelines and implement in their standard operating procedures so that data operations could me robust and more efficient. This will result into cost saving and optimum utilization of man-power and resources/hardwar

Effect of Ge substitution for Si on the anomalous magnetocaloric and magnetoresistance properties of GdMn2Si2 compounds

The effect of Ge substitution on the magnetization, heat capacity, magnetocaloric effect and magnetoresistance of GdMn2Si2-xGex (x=0, 1, and 2) compounds has been studied. The magnetic transition associated with the Gd ordering is found to change from second order to first order on Ge substitution. Magnetic contributions to the total heat capacity and the entropy have been estimated. Magnetocaloric effect has been calculated in terms of adiabatic temperature change (deltaTad) as well as isothermal magnetic entropy change (deltaSM) using the heat capacity data. The temperature dependence of the magnetocaloric effect in all the three compounds have shown broad peaks. The maximum values of deltaSM and deltaTad for GdMn2Ge2 are found to be 5.9 J/kgK and 1.2 K, respectively. The magnetoresistance is found to be very large and positive with a maximum value of about 22% in the case of GdMn2Ge2. In the other two compounds also, the magnetoresistance is predominantly positive, except in the vicinity of the Gd ordering temperature. The anomalous nature of the magnetocaloric effect and the magnetoresistance has been attributed to the canted magnetic structure of these compounds

Memory Utilization in R: The Impact of Data Management Frameworks (Packages)

Memory management is a very important component of running large workloads in computing. It takes into account the capacity & limitations of the available memory on the device itself and deallocates memory space when it is not needed or expands the space through virtual memory. Memory management strives to optimize memory usage so that the CPU can efficiently access the instructions and data it needs to execute the various processes. This work is focused on memory utilization by different data management frameworks in R on different platforms. We have considered Native R, tidyverse, and data.table as data management frameworks. Very high precision (1e-5+1 to 1e-6+1) visual analysis of memory utilization data shows Native R memory management is better when compared to tidyverse and data.table. But, when we are analysing data on a large scale and observe the memory utilization, it shows no significant difference in distribution of memory utilization across different sample sizes. We have established the same results using analysis of variance (ANOVA) and analysis of coefficients of linear regression models

Temperature and magnetic field induced structural transformation in Si doped CeFe2: in-field x-ray diffraction study

Using x-ray powder diffraction technique at various temperatures and applied magnetic fields, we have studied the magnetostructural properties of Ce(Fe0.95Si0.05)2. The x-ray diffraction data establish quantitative relationships between bulk magnetization and the evolution of structurally distinct phases with magnetic field and temperature, and confirm the distinct features of first order phase transition like supercooling and superheating, metastability, and phase co-existence of different structural polymorphs. We observe the lattice volume mismatch across the structural phase transition, which appears to be the cause for the step behavior of the magnetization isotherms at low temperatures. The present study shows that the lattice distortion has to be treated explicitly, like spin, along with the effects of lattice-spin coupling to account for the magnetization behavior of this system. This structure template can resolve the issue of kinetics in this material as observed in different time scale measurements and with different experimental protocols.Comment: 13pages,5 figure

Role of Fe substitution on the anomalous magnetocaloric and magnetoresistance behavior in Tb(Ni1-xFex)2 compounds

We report the magnetic, magnetocaloric and magnetoresistance results obtained in Tb(Ni1-xFex)2 compounds with x=0, 0.025 and 0.05. Fe substitution leads to an increase in the ordering temperature from 36 K for x=0 to 124 K for x=0.05. Contrary to a single sharp MCE peak seen in TbNi2, the MCE peaks of the Fe substituted compounds are quite broad. We attribute the anomalous MCE behavior to the randomization of the Tb moments brought about by the Fe substitution. Magnetic and magnetoresistance results seem to corroborate this proposition. The present study also shows that the anomalous magnetocaloric and magnetoresistance behavior seen in the present compounds is similar to that of Ho(Ni,Fe)2 compounds