Magnetocaloric behavior of REE porphyrin-based paramagnets at room temperature

2019 ◽  
Vol 23 (10) ◽  
pp. 1110-1117 ◽  
Author(s):  
V. V. Korolev ◽  
T. N. Lomova ◽  
A. G. Ramazanova ◽  
O. V. Balmasova ◽  
E. G. Mozhzhukhina
Keyword(s):  
Differential Scanning Calorimetry ◽  
Heat Capacity ◽  
Magnetic Fields ◽  
Single Molecule ◽  
Room Temperature ◽  
Magnetic Behavior ◽  
Entropy Change ◽  
Scanning Calorimetry ◽  
Single Molecule Magnet ◽  
Microcalorimetric Method

REE complexes with cyclic aromatic ligands are ranked as the molecular materials with both electronic functionality and a single-molecule magnet behavior at temperatures lower 80 K. At the temperature close to room, they display a positive magnetocaloric effect (MCE) often comparable with one in ferromagnetics. We were determined MCE during the magnetization of both (5,10,15,20-tetra(4-tert-butylphenylporphinato))ytterbium(III)chloride, (Cl)YbT[Formula: see text]BuPP and (5,10,15,20-tetraphenylporphinato)ytterbium(III)chloride, (Cl)YbTPP in their aqueous suspensions over the temperature range of 278–320 K and in magnetic fields from zero to 1 T by the direct microcalorimetric method. Specific heat capacity in the solid of (Cl)YbT[Formula: see text]BuPP/(Cl)YbTPP has been directly determined in zero magnetic fields using differential scanning calorimetry. Thermodynamic parameters of ytterbium(III) complexes magnetization namely enthalpy/entropy change was determined. To improve understanding of the correlation between (Cl)YbT[Formula: see text]BuPP/(Cl)YbTPP magnetic properties and its electronic structure, we have compared magnetic behavior of paramagnets studied with those for (Cl)MTPP where M = Gd, Eu, Tm.

scholarly journals Electrical resistivity measured by millisecond pulse-heating in comparison to thermal conductivity of the hot work tool steel AISI H11 (1.2343) at elevated temperature

2020 ◽  
Vol 49 (1-2) ◽  
pp. 75-87
Author(s):  
ERHARD KASCHNITZ ◽  
PETER HOFER-HAUSER ◽  
WALTER FUNK
Keyword(s):  
Thermal Conductivity ◽  
Differential Scanning Calorimetry ◽  
Heat Capacity ◽  
Electrical Resistivity ◽  
Tool Steel ◽  
Room Temperature ◽  
Pulse Heating ◽  
Scanning Calorimetry ◽  
Hot Work Tool Steel ◽  
Steel Aisi

Selected thermophysical properties of the hot work tool steel AISI H11 (1.2343) were measured in the temperature range from room temperature to the melting temperature. Thermal diffusivity was measured by the laser-flash method; heat capacity by differential scanning calorimetry; linear thermal expansion by push-rod dilatometry; and density at room temperature by an Archimedean balance. From these experimentally obtained data, thermal conductivity was calculated. Additionally, electrical resistivity of AISI H11 (1.2343) was measured by millisecond pulse-heating in the above mentioned temperature range. The measurement results of electrical resistivity as a function of specific enthalpy was combined with results of specific heat capacity measurements by differential-scanning calorimetry to obtain the relation between resistivity and temperature. Based on measured electrical resistivity and thermal conductivity, a Smith-Palmer-plot for the hot work tool steel AISI H11 (1.2343) is obtained for the ferritic and austenitic phases. No linear behaviour – as expected by the Wiedemann-Franz law – is observed in the ferritic phase region. In the high temperature austenitic region, the thermal conductivity can be computed from electrical resistivity using empirical constants of similar austenitic steels or superalloys.

scholarly journals Высокотемпературная теплоемкость апатитов Pb-=SUB=-10-x-=/SUB=-Nd-=SUB=-x-=/SUB=-(GeO-=SUB=-4-=/SUB=-)-=SUB=-2+x-=/SUB=-(VO)-=SUB=-4-x-=/SUB=- (x=0-3)

2019 ◽  
Vol 61 (7) ◽  
pp. 1397
Author(s):  
Л.Т. Денисова ◽  
Е.О. Голубева ◽  
H.В. Белоусова ◽  
В.М. Денисов ◽  
Н.А. Галиахметова
Keyword(s):  
Differential Scanning Calorimetry ◽  
Heat Capacity ◽  
High Temperature ◽  
Solid State ◽  
Gibbs Energy ◽  
Entropy Change ◽  
Apatite Structure ◽  
Scanning Calorimetry ◽  
High Temperature Heat Capacity ◽  
Temperature Heat

The Pb10-xNdx(GeO4)2+x(VO4)4-x (x = 0 ‒ 3) compounds with the apatite structure have been synthesized from PbO, Nd2O3, GeO2 and V2O5 oxides by the solid-state synthesis with successive burning in air within 773-1073 K. The high-temperature heat capacity of the compounds obtained was determined by differential scanning calorimetry. The CP = f(T) data have been used to evaluate their thermodynamic properties (enthalpy increment, entropy change, and reduced Gibbs energy).

Multifunctional properties of {CuII2LnIII2} systems involving nitrogen-rich nitronyl nitroxide: single-molecule magnet behavior, luminescence, magnetocaloric effects and heat capacity

2021 ◽  
Author(s):  
Hongdao Li ◽  
Pei Jing ◽  
Jiao Lu ◽  
Lu Xi ◽  
Qi Wang ◽  
...  
Keyword(s):  
Heat Capacity ◽  
Magnetic Properties ◽  
Single Molecule ◽  
Nitroxide Radical ◽  
Nitronyl Nitroxide ◽  
Nitronyl Nitroxide Radical ◽  
Single Molecule Magnet ◽  
Luminescence Behavior ◽  
Multifunctional Properties

A family of 3d–4f heterometallic ring-shaped clusters on the basis of a nitrogen-rich nitronyl nitroxide radical have been obtained, and they feature polyfunctionality including magnetic properties, thermodynamics and luminescence behavior.

A Study of the Interactions Between Oligoamidephosphate (OAPh) and Curatives in a Sulphenamide-Accelerated Sulphur Vulcanizing System

1999 ◽  
Vol 19 (2) ◽  
pp. 95-108 ◽  
Author(s):  
Todorka G. Vladkova ◽  
Alexander Chr. Alaminov ◽  
Milka G. Pankova
Keyword(s):  
Differential Scanning Calorimetry ◽  
Zinc Oxide ◽  
Ir Spectroscopy ◽  
Room Temperature ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Sulphur Vulcanization

Abstract The possible interactions between oligoamidephosphate (OAPli) and the curatives of a sulphenamide-accelerated sulphur vulcanizing system were studied by differential scanning calorimetry, IR-spectroscopy, and X-ray analysis. The interactions in double mixtures were between OAPh and zinc oxide (ZnO) and OAPh and sulphur. The OAPh/ZnO interaction that starts at room temperature seems to be the key for understanding the peculiarities of sulphenamide-accelerated sulphur vulcanization in the presence of OAPh.

Influence of Gd Addition on the Structure and Capability of Ni-Mn-In Metamagnetic Shape Memory Alloys

2012 ◽  
Vol 535-537 ◽  
pp. 950-953
Author(s):  
Li Na Bai ◽  
Gui Xing Zheng ◽  
Zhi Jian Duan ◽  
Jian Jun Zhang
Keyword(s):  
Differential Scanning Calorimetry ◽  
Magnetic Properties ◽  
Magnetic Property ◽  
Transition Temperature ◽  
Martensitic Transformation ◽  
Room Temperature ◽  
Vibrating Sample Magnetometry ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray

The influences of Gd concentration on martensitic transformation and magnetic properties of NiMnIn alloys were investigated by differential scanning calorimetry (DSC) , vibrating sample magnetometry (VSM), X-ray diffraction (XRD) and etc. It is Observed through the experiment: the addition of Gd enhances martensite transition temperature;X-ray diffraction analysis of experimental alloys is revealed that to the mixture is martensite and austenite at room temperature; content of Gd is not proportional to the improvement of magnetic property.

Influence of Co-Doping on Magnetic Properties and Magnetocaloric Effect of Fe–Co–Zr–Cu–B Melt-Spun Ribbons

2021 ◽  
Vol 21 (4) ◽  
pp. 2552-2557
Author(s):  
Nguyen Hai Yen ◽  
Nguyen Hoang Ha ◽  
Pham Thi Thanh ◽  
Nguyen Huy Ngoc ◽  
Tran Dang Thanh ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetocaloric Effect ◽  
Melt Spinning ◽  
Room Temperature ◽  
Tangential Velocity ◽  
Magnetic Behavior ◽  
Entropy Change ◽  
Co Doping ◽  
Melt Spun ◽  
Melt Spun Ribbons

In this work, we investigated magnetic properties and magnetocaloric effect in Fe90−xCoxZr7Cu1B2 (x = 0, 1, 2, 3 and 4) melt-spun ribbons. The ribbons were prepared by using a melt-spinning method with a tangential velocity of a copper wheel of 40 m·s-1. The obtained ribbons are almost amorphous. The alloys exhibit typical soft magnetic behavior with low coercivity at room temperature. A minor replacement of Fe by Co gives an increment in Curie temperature (TC) of the alloys to higher temperatures. The TC of the alloys increases from 242 to 342 K with an increase of x from 0 to 4. Maximum magnetic entropy change, ΔSm max, of the alloys, was found to be larger than 0.7 J·kg-1·K-1 in a magnetic field change ΔH of 12 kOe for all the concentrations of Co. High refrigerant capacitys (RC >100 J ·kg-1 with ΔH = 12 kOe) at room temperature region have been obtained for the alloys. The large magnetocaloric effect near room temperature suggests that the alloys can be considered as magnetic refrigerants in the range of 250–350 K.

Study of thermal properties of Ga0.5In1.5Se3 by differential scanning calorimetry

2021 ◽  
pp. 2150407
Author(s):  
S. I. Ibrahimova
Keyword(s):  
Crystal Structure ◽  
Differential Scanning Calorimetry ◽  
Thermal Properties ◽  
Thermal Effects ◽  
Room Temperature ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
Hexagonal Symmetry ◽  
Scanning Calorimetry ◽  
X Ray

The crystal structure and thermal properties of the [Formula: see text] compound have been investigated. Structural studies were performed by X-ray diffraction at room temperature. The crystal structure of this compound was found to correspond to the hexagonal symmetry of the space group P61. Thermal properties were studied using a differential scanning calorimetry (DSC). It was found in the temperature range [Formula: see text] that thermal effects occur at temperatures [Formula: see text] and [Formula: see text]. The thermodynamic parameters of these effects are calculated.

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