Sharp Exothermic Peak Research Articles

Fabrication and characterizations of new glassy Co71Ti24B5 alloy powders and subsequent hot pressing into a fully dense bulk glass

A single glassy phase of Co71Ti24B5 alloy has been synthesized by high-energy ball milling the elemental powders at room temperature, using the mechanical alloying method. The synthetic glassy powder obtained after 130 ks of ball milling exhibits good soft magnetic properties with a polarization magnetization and coercivity values of 1.01 T and 2.86 kA/m, respectively. This ternary glassy alloy in which its glass transition temperature (Tg) lies at a rather high temperature (805 K) crystallizes at 868 K through a single sharp exothermic peak with an enthalpy change of crystallization (ΔHx) of −3.28 kJ/mol. The supercooled liquid region before crystallization, ΔTx of the synthesized glassy powders shows a large value (63 K) for a ternary system. The reduced glass transition temperature (ratio between Tg and liquidus temperatures, Tl(Tg/Tl)) was found to be 0.55. The end product of the glassy powder (130 ks) was compacted in an argon gas atmosphere at 835 K with a pressure of 780 MPa, using the hot-pressing technique. The consolidated sample is fully dense (∼99.5 pct) and maintains its chemically homogeneous glassy structure. The measured polarization magnetization and coercivity values of as-consolidated powders are measured and found to be 0.96 T and 2.92 kA/m, respectively. The Vickers microhardness of the bulk glassy Co71Ti24B5 sample is measured and found to be in the range between 7.32 and 7.46 GPa.

Microstructure and thermal behavior of Sn-Zn-Ag solders

The microstructure and thermal behavior of the Sn-Zn-Ag solder were investigated for 8.73–9% Zn and 0–3.0% Ag. The scanning electron microscopy (SEM) analysis shows the Ag-Zn compound when the solder contains 0.1% Ag. X-ray diffraction (XRD) analysis results indicate that Ag5Zn8 and AgZn3 become prominent when the Ag content is 0.3% and above. Meanwhile, the Zn-rich phase is refined, and the Zn orientations gradually diminish upon increase in Ag content. The morphology of the Ag-Zn compound varies from nodular to dendrite structure when the Ag content increases. The growth of the Ag-Zn compounds is accompanied by the diminishing of the eutectic structure of the Sn-9Zn solder. Differential scanning calorimetry (DSC) investigation reveals that the solidus temperature of these solders exists at around 198°C. A single, sharp exothermic peak was found for the solders with Ag content less than 0.5%. Liquidus temperatures were identified with the DSC analysis to vary from 206°C to 215°C when the Ag content ranges from 1.0% to 3.0%

Thermal Stability of Electrolytes with LixCoO2 Cathode or Lithiated Carbon Anode

AbstractFor Abstract see ChemInform Abstract in Full Text.

Thermal stability of electrolytes with Li xCoO 2 cathode or lithiated carbon anode

The thermal stability of electrolytes with Li x CoO 2 cathode or lithiated carbon anode was reviewed including our recent results. From our experiments, it was found that Li x CoO 2, delithiated by a chemical method using H 2SO 4 showed two exothermic peaks, one beginning at 190 °C and the other beginning at 290 °C. From high-temperature XRD, it was found that the first peak, from 190 °C, was the phase transition from a monoclinic ( R-3 m) to a spinel structure ( Fd3 m). The spinel structure Li x CoO 2 showed a very small cycling capacity. Probably, cation mixing was induced by the heat treatment. The DSC measurements of Li 0.49CoO 2 with 1 M LiPF 6/EC+DMC showed two exothermic peaks. The peak starting at 190 °C probably resulted from the decomposition of solvent due to an active cathode surface, and the peak starting at 230 °C was electrolyte oxidation caused by released oxygen from Li 0.49CoO 2. From DSC profiles of chemically delithiated Li 0.49CoO 2 and 1 M PC electrolytes with various Li salts, it was found that the inhibition effect of the surface reaction starting at 190 °C was large when LiBF 4, LiPF 6, and LiClO 4 were used. The thermal stability of electrochemically lithiated graphite with 1 M LiPF 6/EC+DMC and PVdF-binder has been investigated. DSC revealed a mild heat generation starting from 130 °C with a small peak at 140 °C. The mild heat generation continued until a sharp exothermic peak appeared at 280 °C. The lithiated graphite with the electrolyte without PVdF-binder did not show the small peak at 140 °C. The peak at 140 °C seems to be caused by the reaction (the solid electrolyte interphase (SEI) formation) of the electrolyte and lithiated graphite, which surface is covered by poly(vinylidene fluoride) (PVdF)-binder without formation of SEI at a lower temperature.

Sr4Al14O25: Formation, Stability, and 27Al High-Resolution NMR Characterization

Sr4Al14O25 was synthesized from an aqueous solution of aluminum and strontium nitrates by using a spray-drying process. Its formation was studied by differential scanning calorimetry (DSC) at 5 °C/min and X-ray diffraction (XRD). The amorphous precursor crystallized first, through a sharp exothermic peak at 923 °C, into a mixture of two solid solutions: γ-Al2O3 stabilized by strontium, and SrAl2O4 in its hexagonal form stabilized with excess aluminum atoms. These two solid solutions reacted together through a second exothermic peak at 1134 °C to yield the pure Sr4Al14O25 phase. This compound was found to be stable up to 1500 °C, and decomposed at higher temperatures into SrAl2O4 and SrAl4O7, and then into SrAl2O4 and SrAl12O19. The Sr4Al14O25 local structure was characterized using 27Al magic angle spinning (MAS) and multiple quantum magic angle spinning (MQ-MAS) NMR techniques.

Mechanically induced crystalline–glassy phase transformations of mechanically alloyed Ta 55Zr 10Al 10Ni 10Cu 15 multicomponent alloy powders

New multicomponent Ta-based glassy alloy powder was synthesized by mechanical alloying (MA) the elemental powders of Ta 55Zr 10Ni 10Al 10Cu 15 at room temperature, using a low-energy ball milling technique. During the early stage of milling the agglomerated crystalline powders are mechanically crushed and fresh surfaces are rapidly created. Kneading of such ground powders enhances the atomic diffusion and leads to local alloying. As the MA time increases, the number of vacancies in the Ta lattice (base material) increases so that the atoms of the alloying elements for Zr, Al, Ni and Cu tend to migrate to the open defected lattice of metallic Ta. The number of atoms of the alloying elements that migrate to the bcc lattice of the base material are increasing with increasing MA time and this leads to a monotonic expansion of the Ta lattice. Further milling time (86–130 ks) plays an important role in increasing the rate of diffusion and this leads to an increase in the number of migrated atoms of the alloying elements that pass into the Ta lattice. The a 0 of the yielded solid solution at this stage does not change anymore with increasing MA time and a homogeneous supersaturated bcc-solid solution is obtained after 130 ks of MA time. This solid solution, which is subjected to continuous imperfections, is gradually transformed into a glassy phase upon increasing the MA time. The glassy powders of the final-product (1080 ks) in which its glass transition temperature ( T g) lies at a high temperature (834 K), crystallize through a single sharp exothermic peak at 1004 K ( T x). The total enthalpy change of crystallization (Δ H x) is −10.32 kJ/mol. The width of the supercooled liquid region before crystallization (Δ T x) of the synthesized glassy powder shows the largest value (170 K) of any reported metallic glassy system.

Reaction Synthesis of Aluminum Nitride–Boron Nitride Composites Based on the Nitridation of Aluminum Boride

Aluminum nitride–boron nitride (AlN–BN) composites were prepared based on the nitridation of aluminum boride (AlB2). AlN powder was added to change the BN volume fraction in the obtained composites. Thermogravimetry–differential thermal analysis (TG‐DTA), X‐ray diffractometry, and the nitridation ratio were used to investigate the nitridation process of AlB2. At ∼1000°C, a sharp exothermic peak occurred in the DTA curve, corresponding to the rapid nitridation of aluminum in AlB2. On the other hand, the nitridation of the transient phase, Al1.67B22, was very slow when the temperature was <1400°C. However, the nitridation speed obviously accelerated at temperatures >1600°C. The pressure of the nitrogen atmosphere was also an important factor; high nitrogen pressure remarkably promoted nitridation. Treatment at 2000°C was disadvantageous for nitridation, because of the rapid formation of a dense surface layer that inhibited nitrogen diffusion into the specimen interior. Three specimens, with 5 wt% Y2O3 additive and different BN contents, were prepared by pressureless reactive sintering, according to the determined sintering schedule. Electron microscopy (scanning and transmission) observations revealed that the in‐situ‐formed BN flakes were homogeneously and isotropically distributed in the AlN matrix. A schematic mechanism for microstructural formation was developed, based on the results of nitridation and the microstructural features of the obtained composites. The obtained composites, with a low BN content, exhibited a high bending strength, comparable to that of reported hot‐pressed AlN–BN composites.

Thermoanalytical study of polymorphic transformation in Fluconazole drug

Polymorphic transformation in Fluconazole (I) drug has been studied employing differential scanning calorimetry (DSC), X-ray diffraction and FT-IR techniques. Fluconazole (I) exhibited the sharp melting point at 138.4 °C. Considerable under cooling was, however, observed for the drug during cooling. No indication of freezing of molten Fluconazole (I) was evident in the DSC curve recorded up to a temperature of 25 °C in the cooling cycle. Reheating of the sample obtained after cooling, produced the DSC pattern much different compared to that obtained in the first heating and consisted of a sharp exothermic peak beginning at 81 °C preceding the twin endothermic peak with an onset temperature of 135.3 °C. In addition to these two peaks, a small endothermic peak was also observed around 31 °C, which could be attributed to a glass transition with an associated relaxation. The precise glass transition temperature derived from the data collected from six different independent experiments was found to be (31.67±0.13) °C. X-ray diffraction pattern of the Fluconazole (I) indicated that the as received sample was crystalline. The molten Fluconazole on cooling, however, produced a glassy amorphous mass. The amorphous product on heating to temperature >81 °C transformed to Fluconazole (II) which subsequently changed to Fluconazole (I) prior to melting. The split endothermic peak beginning at 135.3 °C recorded for the solidified Fluconazole sample is consistent with the observations made by X-ray diffraction. The observations made by employing DSC and X-ray diffraction were corroborated by FT-IR data on the samples isolated at different stages in the experiments.

A thermoanalytical study on the oxidation of ZrC and HfC powders with formation of carbon

Abstract The oxidation of ZrC and HfC powders was thermoanalytically investigated by simultaneous thermogravimetry (TG), differential thermal analysis (DTA) and mass spectrometry (MS) at various oxygen pressures (PO2) between 0.5 and 40 kPa in the temperature range 20–1000 °C. TG results showed that the oxidation of ZrC and HfC begins at a fixed temperature of 380 and 400 °C, respectively, independent of PO2 and the type of sample. The degree of reaction, defined for the complete carbide–oxide transformation, reached a maximum of 103–160%, then gradually returning to 100% at higher temperatures. For the oxidation of ZrC, a sharp exothermic DTA peak appeared at PO2≥10 kPa with the corresponding CO2 evolution but broad DTA and CO2 evolution peaks occurred at PO2≤5 kPa. The oxidation of HfC gave two exothermic DTA peaks at all pressures, the higher temperature peak agreeing with the CO2 evolution. Oxidation exceeding 100%, related with the formation of carbon, is discussed from the results of TG, DTA, MS and X-ray analysis.

Thermal stability of graphite anode with electrolyte in lithium-ion cells

Thermal stability of electrochemically lithiated graphite with 1 M LiPF 6/EC+DMC and PVdF-binder has been investigated. DSC measurements using an airtight sample case reveal a mild heat generation started from 130 °C with a small peak at 140 °C. The mild heat generation continued until a sharp exothermic peak appeared at 280 °C. The heat evolved in the small peak at 140 °C decreased by storage of the lithiated graphite with PVdF and the electrolyte at 50 °C for 3 days before the DSC measurements. The lithiated graphite with the electrolyte without PVdF-binder did not show the small peak at 140 °C. The peak at 140 °C seems to be caused by the reaction (the Solid Electrolyte Interphase (SEI) formation) of the electrolyte and lithiated graphite, whose surface is covered by poly(vinylidene flouride) (PVdF)-binder without formation of SEI at a lower temperature. The mild heat generation from 140 to 280 °C is the reaction of the lithiated graphite and the electrolyte through SEI (SEI formation), because there was no such mild heat generation when non-lithiated graphite was used. The peak at 280 °C is probably a direct reaction of lithiated graphite and electrolyte by a breakdown of SEI.

Assessment of amorphous content by microcalorimetry

The amorphous content of model drugs was evaluated by isotherm microcalorimetry. Two model drugs were employed; lactose as a hydrophilic one and erythromycin as a hydrophobic one. When amorphous lactose was loaded in a sample cell with a water vial, a sharp exothermic peak due to the crystallization was observed. When a mixture of the amorphous and the crystalline forms was loaded, the peak area of the exothermic heat flow was proportional to the amorphous content. Quantification could be done with much higher accuracy than by the X‐ray powder diffraction method reported in earlier literature. When erythromycin was used as a model drug, the crystallization was not completed by water but by organic solvents, which can dissolve erythromycin. The most adequate solvent for erythromycin was acetonitrile, of which the suitability was elucidated in terms of solubility and vapor pressure. This is the first report in which the role of the vapor pressure on crystallization behavior is discussed. The time needed to obtain the crystallization peak was controlled by mixing acetonitrile with water. The strategy to obtain the crystallization peak by microcalorimetry, which enables quantification of the amorphous content with high accuracy, is discussed.

Synthesis and characterization of CuO containing mesoporous silica spheres

A new series of mesoporous silica spheres containing nanodispersed copper oxides were synthesized in H2O/EtOH/ammonia solution at room temperature. The mesoporous structures were characterised using X-ray powder diffraction and N-2 adsorption-desorption techniques. Scanning electron micrograph and transmission electron micrograph revealed that the MCM-41 particles have spherical morphologies. The DTA curve of pure MCM-41 exhibited a sharp single exothermic peak between 290degreesC and 340degreesC, while a broad peak with several shoulders in the temperature range between 180degreesC and 380degreesC was observed for Cu-MCM-41, indicating the possible complexation of Cu2 with surfactants adhering to the inner surfaces of the mesopores. Electron paramagnetic resonance spectra of uncalcined samples revealed that Cu2 ions are in an octahedral or distorted octahedral coordination with nitrogen ligands of the surfactant while in the calcined samples they are coordinated with oxygen of the MCM-41 framework. The redox properties of samples were examined by a temperature-programmed reduction and N2O passivation method. The results indicate that CuO with increasing particle size could be formed in the mesoporous materials with increasing Cu contents, and this decreased the reducibility of the resulting CuO. (C) 2002 Kluwer Academic Publishers.

Mechanically Induced Solid-State Reaction for Synthesizing New Multicomponent Ta<SUB>55</SUB>Zr<SUB>10</SUB>Ni<SUB>10</SUB>Al<SUB>10</SUB>Cu<SUB>15</SUB> Glassy Alloy Powders with Extremely Wide Supercooled Liquid Region

New multicomponent Ta-based glassy alloy powder was synthesized by mechanical alloying a mixture of elemental Ta55Zr10Ni10Al10Cu15 powders at room temperature, using a low-energy ball mill. The glassy powders of the final-product (1080 ks) in which its glass transition temperature (Tg) lies at a high temperature (834 K), crystallize through a single sharp exothermic peak at 1004 K (Tx). The total enthalpy change of crystallization (ΔHx) is −10.32 kJ/mol. The supercooled liquid region before crystallization (ΔTx) of the synthesized glassy powder shows the widest value (170 K) of any reported metallic glassy system.

Thermal analysis of acrylonitrile polymerization and cyclization in the presence of N, N-dimethylformamide

This paper examines the polymerization of acrylonitrile to poly(acrylonitrile)(PAN), and its cyclization, in bulk form and using N,N-dimethylformamide (DMF) as solvent in which both monomer and polymer are soluble. Thermal analysis of the resultant products after polymerization has been performed by DSC and pyrolysis gas chromatography/mass spectrometry (Py-GC/MS). Scanning electron microscopy has been used to study the morphology of the resultant products and after thermal treatments. The DSC thermal curve of PAN-DMF sample is quite different from the PAN bulk sample, showing a single sharp exothermic peak associated with nitrile group polymerization (cyclization) of PAN at lower temperature (240°C) than that of bulk PAN sample (314°C). Cyclization of PAN was confirmed by IR spectroscopy. It was found that the amide molecules are difficult to eliminate completely in the product obtained after the polymerization reaction, even after prolonged heating at 110°C, and remain occluded. The formation of a complex by dipolar bonding is also possible and it is discussed. It is concluded that the amount of heat evolved as well as the temperature interval over which it is released are influenced by the chemical processing of PAN when using DMF as solvent of both monomer and polymer. Pyrolysis of these PAN samples revealed the release of occluded molecules of DMF, and several compounds containing nitrogen produced from the thermal degradation processes. All these results are interesting to know the chemical processing of carbon fibres and activated carbon fibres from PAN modified precursors.

Aqueous Syntheses of Forsterite (Mg 2 SiO 4 ) and Enstatite (MgSiO 3 )

Forsterite MgSiO4 and enstatite MgSiO3 were synthesized by two different aqueous processes. TEOS was directly hydrolyzed in aqueous solutions of magnesium nitrate, giving solutions of magnesium nitrate and silicic acid. For the first process these solutions were spray-dried and the powders heat treated to decompose the nitrate; and for the second one they were precipitated in a solution of ethylenediamine as a base, the resulting precipitate was filtered, washed and dried. Spray-dried or precipitated, no specific thermal event was detected by thermal analysis for the crystallization of forsterite (500–1000°C) while a strong and sharp exothermic peak traduced the crystallization of enstatite at 800°C. Very minor secondary phases could be detected by X-ray diffraction up to 1200°C for the spray-dried powders, while the precipitated powders presented a higher chemical homogeneity, but much care had to be taken for a quantitative precipitation. As some minor secondary phases like SiO2 or some polymorphs of MgSiO3 could be not detected by XRD up to 1300°C, higher thermal treatments were necessary to control the purity or the desired phase.

Thermal study of the effect of several solvents on polymerization of acrylonitrile and their subsequent pyrolysis

The polymerization of acrylonitrile to polyacrylonitrile (PAN) has been studied using several solvents: N, N-dimethylformamide (DMF), hexane, toluene, water, and in bulk form (no solvent). The addition of DMF is the only case where both monomer and polymer are soluble in the solvent. Thermal analyses of the resultant products after polymerization have been performed by differential scanning calorimetry and pyrolysis–gas chromatography/mass spectrometry. The effect of the solvents employed as media for polymerization is interpreted from the results of the thermal and structural (X-ray diffraction) methods. The polymer samples obtained when using water or toluene as solvents have the greater content of amorphous components compared to the others. The amide molecules are difficult to completely eliminate in the product obtained after the polymerization reaction and even after prolonged heating at 110°C and remain occluded. DMF can be considered to exert a plasticized effect on PAN and is even capable of forming complexes by dipolar bonding. As a result of this interaction, the thermogram is quite different from the other samples studied in the present work, showing a single sharp exothermic peak. This is associated with nitrile group polymerization (cyclization) of PAN. It is deduced that the amount of heat evolved as well as the temperature interval over which it is released are influenced by the chemical processing of PAN, in particular when using DMF as solvent for both monomer and polymer. Pyrolysis of the different PAN samples revealed the release of occluded solvent molecules, mainly when using DMF, and compounds produced from the thermal degradation processes. Different types of cyclized compounds, such as pyridine derivatives and aromatic nitriles were identified. All these compounds could be derived from cyclized PAN structures which are not completely degraded by the thermal treatment of pyrolysis. Alkyldinitriles have also been tentatively identified associated with the final molecular breakdown of cyclized structures with six-member rings by pyrolysis. Valuable complementary information on the structure of the PAN samples (homopolymer) obtained using the different processing approaches involving several solvent media has been provided by pyrolysis. The present results will improve our understanding of the evolution of the structure and properties of carbon and activated carbon fibres which will enable us to establish processing strategies in order to obtain these materials under adequate and reproducible conditions.

Crystallization behavior and characteristics of mullites formed from alumina–silica gels prepared by the geopolymer technique in acidic conditions

Abstract Mullites were prepared by the geopolymer technique to obtain nanometer sized mullite polycrystals. Sodium silicate solutions prepared from Na 2 O·SiO 2 ·9H 2 O (A-series) and Na 2 O·2SiO 2 ·aq (B-series) were applied as host solutions. Then, Al-nitrate guest solution was added drop by drop into the host solutions to obtain precipitates, which were filtrated and washed by deionized water. The air-dried precursor gels thus obtained were fired at elevated temperature up to 1400°C and were examined by XRD, DTA and ICP techniques. The XRD results showed that the A-series gels began to crystallize mullite at about 1000°C, while the B-series at about 1100°C. According to the DTA, a sharp exothermic peak appeared at about 1000°C in the A-series gels indicating polymer character of the gels, while no such a peak in the B-series gels indicating nonpolymer character of the gels. Chemical analysis by ICP revealed low concentration of Al 2 O 3 -component in the gels, and this caused the gels consisted of mullite and silica potentials. Na-contaminations were extremely low. The process of mullite generation was also discussed on the basis of cell-parameters measured.

Thermal Analysis and X-ray Diffraction of Synthesis of Scheelite

Scheelite (calcium tungstate)is the product of one of the processing methods of wolframite by its roasting with calcium oxide or limestone or its fusion with calcium chloride, followed by acid processing of calcium tungstate with the formation of tungstic acid. Scheelite occurs in contact metamorphic deposits, hydrothermal veins and pegmatites.The present work illustrates a thermal analysis study of synthesis of scheelite by sintering of wolframite with calcite and sintering of tungsten oxide with calcite or calcium oxide using a derivatograph. The reaction products were identified microscopically and by using a Siemens Crystalloflex diffractometer.The DTA curve of sintering of wolframite with calcite shows the beginning of the reaction at 560°C with the formation of scheelite. The intensive formation of scheelite is represented by the medium and wide endothermic peak at 740°C. This is followed directly by a large and sharp endothermic peak at 860°C, representing the dissociation of unreacted calcite.The DTA curve of tungsten trioxide shows three thermal effects. The sharp exothermic peak at 320°C represents the oxidation of tungsten oxide content of lower valency. The endothermic peaks at 750 and 1090°C are related to polymorphic changes of tungsten trioxide. The beginning of its sublimation is observed at temperature higher than 800°C.The DTA curves of sintering of tungsten trioxide with calcite or calcium oxide indicate that the intensive formation of scheelite takes place by endothermic reactions at 660 and 545°C respectively. The medium and small endothermic peaks at 520 and 730°Con the DTA curve of tungsten trioxide with calcium oxide represent the dehydration of calcium oxide and the loss of carbon dioxide due to some carbonatization of calcium oxide with carbon dioxide from air, respectively.The produced scheelite is colorless in thin sections, has distinct cleavage (101), crystallizes in the tetragonal system in the form of tabular crystals and is optically positive.

Structural and soft magnetic properties of Fe 73.5Nb 3M 1Si 13.5B 9 (M=Cu, Mn, Pt)

The magnetic and the structural properties have been investigated for Fe 73.5Nb 3M 1Si 13.5B 9 (M=Cu, Mn, Pt) alloys in their as-received and heat-treated state. Differential scanning calorimeter and scanning electrical resistivity were used to study crystallization behaviour and to examine the influence of the nucleation elements Cu, Mn and Pt on the structural and magnetic properties of Fe-based nanocrystalline materials. The temperature coefficient of resistivity above Curie temperature was found to be very low (0.2×10 −4 K −1) in the Cu containing alloy as compared to the alloys which contained Mn or Pt. A broad exothermic DSC peak for the formation of Fe 3Si nanoparticles was absent when Cu was replaced by Mn or Pt. Instead, a sharp exothermic peak for the formation of Fe 3(SiB) phase was observed with an onset at 875 K. The magnetic properties of the three alloys measured after stress relaxed annealing were similar. However, after first-stage crystallization, the soft magnetic properties were further enhanced only in Cu containing alloys due to the formation of Fe 3Si nanoparticles. Such nanoparticles together with different intermetallic phases like FeMn 3 or FePt 3 were formed in Mn or Pt containing alloys. Moreover, the NbFeSi phase was also formed in the latter alloys after higher temperature annealing which reduced not only the amount of the Fe 3Si phase but also the grain refining effect due to the lesser amount of Nb available at the grain boundary. When Cu was replaced by Mn or Pt, the formation of different intermetallics reduced the volume fraction of Fe 3Si nanoparticles and the lesser amount of grain refining Nb made the materials magnetically inferior after annealing above 775 K.

Synthesis and characterization of the nonstoichiometric perovskite-type compound ScRh 3B x

Polycrystalline samples of ScRh 3B x (0≤ x≤1.0) were synthesized by the arc melting method. The crystal structure is the perovskite-type cubic structure (space group Pm3m) for boron content in the range 0≤ x≤1.0 (0–20 at.% B). The lattice parameter a varies linearly from a=0.3903(1) nm ( x=0) to 0.40799(3) nm ( x=1.0). The micro-Vickers hardness increases with increasing boron content from 1.9 (±0.1) GPa for ScRh 3 (0 at.% B) to 9.9 (±0.1) GPa for ScRh 3B 1.0 (20 at.% B). Thermogravimetric analysis indicates that the oxidation onset temperature for stoichiometric ScRh 3B is 868 K. A sharp exothermic peak is observed at 1068 K by differential thermal analysis. The weight gain of the sample by heating in air up to 1473 K is 12.7%. The weight gain increases with increasing boron content. All samples in the range 0≤ x≤1.0 show a metallic temperature dependence of the resistivity down to 0.5 K. Magnetic susceptibilities also show Pauli paramagnetic behavior and no trace of magnetic transitions on superconductivity in any of the samples.