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This study investigates the influence of La 2 O 3 addition on the structural, physical, and radiation shielding properties of basalt-based glasses. Incorporating varying concentrations of La 2 O 3 (0, 10, 20, 30 wt%) into basalt glasses, we aimed to evaluate the potential of La 2 O 3 in enhancing the material's effectiveness against gamma radiation. Utilizing Ba-133 point radioactive source and Ultra Ge detector, we measured the attenuation parameters in different photon energies (81, 160, 223, 276, 302, 356, and 383 keV). The glasses exhibited an amorphous structure, as confirmed by XRD analysis, with density values ranging from 2.72 to 3.305 g/cm³, increasing with La 2 O 3 content. The microstructural analysis indicated that La3+ ions predominantly integrate into the glass matrix, enhancing the structural integrity without forming separate phase regions. Our findings demonstrate a significant improvement in radiation protection parameters, including mass attenuation coefficients and half-value layers, with higher La 2 O 3 concentrations. These outcomes were also supported by the data obtained for Z eff and EBF values of G1-G4 glasses. The mechanical properties of the glasses were also investigated with the Makishima-Mackenzie model and it was observed that the elastic moduli were also affected by the addition of La 2 O 3. The enhancements observed with La 2 O 3 additions suggest promising avenues for developing advanced shielding materials, combining the inherent advantages of basalt glasses with the high atomic weight and electron density of lanthanum compounds. [ABSTRACT FROM AUTHOR]

Due to the specific affinity of lanthanum (La) toward phosphate over a wide pH range, La compounds such as lanthanum oxide (LO), lanthanum hydroxide (LH), and lanthanum carbonate (LC) have been integrated into various La-based adsorbents in recent years. In order to evaluate the differences among LO, LH, and LC in terms of phosphate removal performance (adsorption capacity, pH-dependent behavior, and selectivity), stability (La leaching), and reusability, data from the literature are consolidated. Furthermore, key properties of the respective compounds such as solubility and speciation are examined to identify possible underlying reasons. LC exhibits superior adsorption capacity and a wider optimum pH range for phosphate binding and lower La leaching, but reusability data of the various compounds remain inconclusive. Based on their superior performance and stability in laboratory studies, LC may have greater lifespan and can serve as a viable alternative to LO and LH for future studies on phosphate removal in order to maximize phosphate removal efficiency while simultaneously reducing secondary pollution. To further develop La-based adsorbents for phosphate removal and recovery, direct comparisons are needed among La compounds using more complex matrices such as wastewater and river water. Furthermore, the role of crystal structure in the phosphate removal performance of different compounds must be carefully assessed. Finally, to evaluate the feasibility of practical application and understand the effects of continuous flow operation on phosphate removal and recovery efficiency, more pilot-scale studies involving La-based adsorbents should be conducted. Performance, stability, and reusability of different La compounds are crucial to the practicability of La-based adsorbents for phosphate removal along with addressing key challenges associated with real-world usage. The simultaneous incorporation of other metals presents a possible way to improve on the inherent properties of La-based adsorbents to enable them to better address these challenges. [ABSTRACT FROM AUTHOR]

In the model manganese perovskites La1−xCaxMnO3, several important phenomena have been observed, including ferromagnetic metallic/insulating states, colossal magnetoresistance effects, and charge- and orbital-ordered states. In the past, only compounds with x = 1/2, 2/3 and 3/4 and an insulating ground/antiferromagnetic state have been studied. To fully understand the crystal and electronic structures of these materials, it is important to study compounds with doping levels in the range of 0.5 < x < 2/3. Here we study the crystal structure in a series of compounds with 0.5 < x ≤ 0.6 using ultrahigh-resolution synchrotron X-ray diffraction. The experimental results reveal that all compounds undergo a structural transition at T < TCO(x) ≈ 200 − 220 K with the concomitant emergence of superlattice Bragg peaks, which can be indexed assuming a superstructure with a modulation propagation vector, τ. At the base temperature of 5 K, the modulation vector of the superstructure τ = [τa, 0, 0] is parallel to the a-axis, with τa varying linearly with x, as τa ≈ 1 − x. Our results may aid attempts to understand more deeply phenomena related to spin, charge, and orbital ordering, as well as colossal magnetoresistance and symmetry breaking and emergent order in quantum states. Doped lanthanum manganite compounds exhibit a range of conducting, electronic and magnetic phases, and, in the case of the Ca-doped series, a phase transition from a ferromagnetic metal to an antiferromagnetic insulator occurs. Here, the authors use ultrahigh-resolution synchrotron X-ray diffraction to track the complex structural behavior of La1−xCaxMnO3 below the charge-ordering temperatures. [ABSTRACT FROM AUTHOR]

A series of LaF3:Ce3+ phosphors for application in photodynamic therapy are synthesized using a one-stage solvothermal synthesis. The synthesis conditions; type and quantity of stabilizer; concentration of activator providing the maximum intensity of UV- and X-ray-excited luminescence; lowest size; and highest colloidal stability of the phosphor nanoparticles are found. As a result of this study, the following parameters are determined using cerium content 5% mol. ethanol as the reaction medium for the solvothermal synthesis and polyvinylpyrrolidone as the stabilizer at an optimized amount. [ABSTRACT FROM AUTHOR]

We experimentally investigated the photo-induced direct current (DC) drift of a lead lanthanum zirconate titanate (PLZT) Mach-Zehnder modulator with large optical input power. We clarify the mechanism by which short-term and long-term DC drifts arise and discuss each case of DC drift. We reveal that short-term DC drift can be reduced by adjusting the buffer-layer resistivity of the PLZT modulator. We also found that the impurity level of the buffer layer affects long-term DC drift. [ABSTRACT FROM AUTHOR]

Temperature is one of the key factor that affecting the electrical, physical, structural, and morphological properties as well as the crystallinity of the nanomaterials. The current study investigates the effect of annealing temperature on the structural and electrical properties of lanthanum oxide (La2O3) thick films. La2O3 thick films were prepared on a glass substrate using a conventional screen printing technique. In this work, T1 is an unannealed prepared film, whereas T2 and T3 are annealed in a muffle furnace for 3 hours at 350°C and 450°C, respectively. XRD technique was exploited to investigate the crystallization behavior of the films. It was found that the crystal structure of La2O3 thick films are pure hexagonal phase. The annealing temperatures were revealed to have influence on the crystallite sizes of the films. SEM and EDS was used to study the morphology and elemental analysis of the films respectively. The electrical properties of the films were explored by measuring resistivity, temperature coefficient of resistivity (TCR), and activation energy at lower and higher temperatures regions. The film annealed at 450°C has high resistivity, a high TCR, and small crystallite size. The thickness of the La2O3 thick films was also found to decrease as the annealing temperature increased. [ABSTRACT FROM AUTHOR]

Lanthanum manganite (LMO) thin films were deposited by co-sputtering La and Mn targets in an Ar and O2 gas mixture. The films were synthesized on silicon and fused silica substrates. The influences of thermal annealing on the structure, optical and electrical properties of LMO films were investigated. The results exhibited a correlation between these properties. In the amorphous state, an increase in annealing temperature improved the optical transmission and decreased the electrical capacitance. The beginning of crystallization at 600 °C was manifested by a strong increase in the capacitance and a decrease in the optical transmission. At higher annealing temperature, polycrystalline films were obtained with different optical and electrical characteristics. On the other hand, the annealed LMO films showed a photocurrent effect during exposure to a weak LED light. [ABSTRACT FROM AUTHOR]

Using a variety of physicochemical characterization techniques, we have determined the composition and chemical formula of lanthanum and neodymium compounds with phthalic acid, synthesized for the first time. The compounds have been shown to have similar chemical formulas: La2(L)3·7H2O and Nd2(L)3·6H2O. We have examined the thermal destruction of the synthesized compounds. The proposed schematic structure of the La complex consists of zigzag 2D polymer layers, which are cross-linked by water molecules to form a 3D structure—a supramolecule. [ABSTRACT FROM AUTHOR]

La 4 Co 3 O 9 perovskite thin film was grown on a glass substrate using spray pyrolysis technique at 460 °C. X-ray diffraction (XRD) pattern indicates a high orthorhombic structure in Ruddlesden-Popper phase along (040) orientation. A nanometric scale size varying between 10 and 20 nm of the La 4 Co 3 O 9 films were proved via Transmission Electron Microscopy (TEM). The High-Resolution Transmission Electron Microscopy (HRTEM) specifically displayed the lattice fringe among the (040) and (1 10 0) planes. A direct transition band was revealed in the synthesized La 4 Co 3 O 9 films through transmittance and reflectance spectra, with a band gap of 1.42 eV. Urbach effect as well as a relatively high absorptivity were evidenced. The prepared thin films exhibit a ferromagnetic behaviour. The saturated magnetization (M S) and coercive field (H C) were equal to M S = 4.69810−4 emu/g and an H C = 45.56 Oe, respectively, at room temperature. The revealed ferromagnetic behaviour was due to the non-stoichiometry of La 4 Co 3 O 9 constituents. The present work emphasizes the specificity and suitability of La 4 Co 3 O 9 thin film perovskite for magneto-optical applications. [ABSTRACT FROM AUTHOR]

A bifunctional electroactive filter was rationally fabricated for simultaneous oxidation and sequestration of toxic trivalent arsentic As ( Ⅲ ). A novel nanoscale La(OH)3 modified electrochemical carbon nanotube ( CNT ) network filter was prepared by a facile electrodeposition strategy. The As ( Ⅲ) decontamination kinetics and adsorption capacity were both found to increase with the flow rate ( 1. 5 - 6. 0 mL/ min) and the applied voltage ( 0 - 2. 5 V). The CNT filter hybridized with La (OH)3 ( CNT-La(OH)3 ) has demonstrated the ultra-high adsorption capacity of 750. 2 mg / g for As ( Ⅲ), which is ascribed to the combined role of sufficient adsorption sites, flow-through filtration and electric field. XPS analysis revealed that the As ( Ⅲ ) decontamination mechanism involved a two-step adsorption-oxidation process. The formation of inner-sphere La-O-As complexes, ligand exchange and electro-adsorption are all parts of the As(Ⅲ) adsorption process. The adsorbed neutrally-charged As(Ⅲ) was further oxidized to negatively-charged As ( V) when aided by an electric field, which could be effectively sequestrated by La(OH)3 . The CNT-La(OH)3 filter shows high stability under alkaline conditions and can be regenerated with dilute NaOH solution. In this study, all experiment results have demonstrated a promising and effective CNT-La ( OH)3 electrochemical filter for As (Ⅲ) pollution minimization. [ABSTRACT FROM AUTHOR]

In this work Full Potential study performed on Lanthanum compounds to analyze its photovoltaic properties. Five different combinations of Lanthanum and Indium with phosphorus are chosen in this study are La 3 P, La 2 InP, LaIn 2 P, LaP and InP. The optical, structural, thermoelectric, thermal, and electronic properties of all the above-mentioned compounds are analyzed using Density Functional Theory (DFT) applied in the WIEN2k software. Based on the analysis of electronic properties is concluded that La 3 P, LaP, La 2 InP and LaIn 2 P are conductors whereas InP is semiconductor (direct band gap) with band gap (energy) value 0.39 eV. The optical properties analysis shows these materials have desirable properties in the near UV or in the UV region. The low value of Gibbs energy indicates high thermodynamic stability. Power factor values for La 2 InP, LaP, InP and La 3 P are found to be in agreement with existing thermoelectric material, rendering them as potential thermal photovoltaic materials. [Display omitted] • Full Potential study performed on Lanthanum compounds to analyze its photovoltaic properties. • Five different combinations of Lanthanum and Indium with phosphorus are chosen for this analysis. • Density Functional Theory (DFT) as implemented in WIEN2k software were used to investigate different properties. • Power factor values of La 2 InP, LaP, InP and La 3 P confirm good thermoelectric properties. [ABSTRACT FROM AUTHOR]

In this study, zinc oxide (ZnO) nanofibers were prepared using the electrospinning method, and the effects of different spinning voltages and annealing temperatures on the fiber structure were tested. La 0.8 Sr 0.2 FeO 3 (LSFO) perovskite film was prepared by a sol-gel method. Then we dip LSFO on ZnO nanofiber and grow it on the interdigital gold electrode substrate for gas sensors. The results show that the ZnO/LSFO heterostructure gas sensor has a good sensing response to H 2 S gas and exhibits good gas selectivity. The best gas response is 52.17% under 4 ppm H 2 S and work temperature 200°C, which has good recovery and reproducibility. [ABSTRACT FROM AUTHOR]

The chemical bath deposition technique was employed to synthesize unsubstituted and different percentages of La-substituted ZnO-nanoscaled thin films on a glass substrate with nominal concentrations of 0.0%, 3%, and 7%. Microwave irradiation effects on the photocatalyst of La-substituted ZnO samples for photodegradation of Congo red dye were investigated. Crystallographic parameters of unsubstituted and La-substituted ZnO were scrutinized by XRD. It was verified that as-synthesized samples belong to the wurtzite structure. Chemical stretching of the as-prepared samples was detected using an FTIR spectrum which reflects that La substitutes in ZnO lattice. A peak of 1630 cm−1 is presently owing to the ZnO stretching and deformation. The band gap of unsubstituted and La-substituted ZnO was evaluated using a UV–Vis spectrometer, and it was substantiated that the energy band gap suppresses as La content enhances which states the existence of red shift. The electric property such as resistance of unsubstituted and La-substituted ZnO nanomaterial was intended by I–V characteristics. The optical property with surface defect study was elucidated by fluorescence spectroscopy. Visible light photosensitivity was intended by I–V characteristics. [ABSTRACT FROM AUTHOR]

In the present work, LaNi0.5Ti0.5O3 and La2NiTiO6 nanoparticles were synthesized by the modified Pechini method. LaNi0.5Ti0.5O3 was calcined at 1073 K for 17 h or 100 h, while La2NiTiO6 was calcined at 1273 K for 135 h. The double perovskite calcined at 1073 K for 17 h presented orthorhombic symmetry with Pbnm space group, mean particle size was 31.9 ± 1 nm, random ordering of Ni2+ and Ti4+ cations, Néel temperature close to 15 K, and magnetic moment of 1.29 μ B . By increasing the calcination time, this material showed the same symmetry and space group, a mean particle size of 50.7 ± 2 nm, short-range ordering of Ni2+ and Ti4+ cations, Néel temperature around 12 K, and magnetic moment of 0.96 μ B . La2NiTiO6 presented a monoclinic crystal structure, with P21/n space group, mean particle size of 80.0 ± 5 nm, rock salt ordering of Ni2+ and Ti4+, Néel temperature of approximately 23 K, and magnetic moment of 2.75 μ B . [ABSTRACT FROM AUTHOR]

Wastewater treatment via photocatalytic activity is one of the most economical and environment-friendly method. However, obtaining an efficient photocatalyst remains a challenge for researchers in this most emerging field. In this study, pure and lanthnum (La)-(1%,2% and 3%) doped zinc oxide nanoparticles (ZnO-NPs) were synthesized via sol gel chemical technique to investigate their optical, chemical and structural properties. The synthesized NPs were characterized by using UV/VIS, SEM, EDS, XRD, FTIR, PL and Raman spectroscopy. Such nanoparticles (NPs) have been used as a photocatalyst for the degradation of rhodamine B (RhB) dye. Quite interestingly, the La-doped ZnO-NPs show unique results associated with the fact that by varying the concentration of dopant, the particle size is reduced (28.09 ± 0.04 nm to 15.85 ± 0.02 nm), which leads to a decrease in band gap, i.e., shifting toward visible (3.26 eV to 3.06 eV). This attributes to the fact that doping also helps to reduce electron–hole pair recombination rate during photocatalysis, which makes La-doped ZnO-NPs the most potential photocatalyst against RhB dye. We report a maximum degradation efficiency of 84.97% in 150 min observed from La0.02Zn0.98O, which reveals that 2% doping of La is the optimal value whereas further increase in concentration, i.e., at 3% (La) band gap increases whereas degradation efficiency reduces from 84.97 to 73.37%. [ABSTRACT FROM AUTHOR]

The Kondo effect has been a topic of intense study because of its significant contribution to the development of theories and understanding of strongly correlated electron systems. In this work, we show that the Kondo effect is at work in La1−xPrxNiO3−δ (0 ≤ x ≤ 0.6) thin films. At low temperatures, the local magnetic moments of the 3d eg electrons in Ni2+, which form because of oxygen vacancies, interact strongly with itinerant electrons, giving rise to an upturn in resistivity with x ≥ 0.2. Observation of negative magnetoresistance, described by the Khosla and Fisher model, further supports the Kondo picture. This case represents a rare example of the Kondo effect, where Ni2+ acts as an impurity in the background of Ni3+. We suggest that when Ni2+ does not participate in the regular lattice, it provides the local magnetic moments needed to scatter the conduction electrons in the Kondo effect. These results offer insights into emergent transport behaviors in metallic nickelates with mixed Ni3+ and Ni2+ ions, as well as structural disorder. [ABSTRACT FROM AUTHOR]

The incorporation of lanthanum (La) into sol-gel based aluminum-oxide (Al 2 O 3) dielectrics is investigated by analyzing the dielectric properties obtained from electrical capacitive measurements of metal-insulator-metal. The optimized La doping results in significantly suppressed variation of frequency-dependent capacitance of sol-gel based La-doped Al 2 O 3 (LaAlO 3) dielectrics even at high frequencies of ~ MHz. In addition, flexible temperature sensors with sol-gel based LaAlO 3 dielectrics on polyimide substrates are demonstrated through investigations on the capacitive responses to different temperatures ranging from 30 to 200 °C at various frequencies from 100 Hz to 1 MHz. Without any buffer or passivation film, the proposed flexible temperature sensors achieved a high mechanical stability against cyclic bending tests with curvature radii from 10 to 5 mm. Finally, the feasibility of a healthcare monitoring system is demonstrated by utilizing wearable body-temperature sensor arrays consisting of sol-gel based LaAlO 3 dielectrics. High-performance temperature sensor system is capable of analyzing interfacial temperature characteristics on human body between 30 and 40 °C in real-time and displaying them on the use's smartphone. We believe that this study is expected to significantly contribute to the field of wearable bioelectronics consisting of solution-processed metal-oxide dielectrics for healthcare monitoring systems. [ABSTRACT FROM AUTHOR]

Two LaxMn1−xOy (LM1, LM2) and three LaxFe1−xOy (LF1, LF2, LF3) amorphous nanowire arrays (NWAs) were prepared by chemical co‐precipitation in anodic aluminium oxide (AAO) templates. The concentration of the reactant plays a crucial role in determining the morphology of LaxMn1−xOy NWAs. The AAO template was etched using a mixed nitrate solution that led to the exposure of LaxFe1−xOy NWAs on the template surface in the process of preparation, then the length of nanowires exposed to the template depends on the etching time. The LM2 NWAs exhibited obvious magnetic anisotropy after the template is almost eliminated by etching with NaOH solution, while the magnetic anisotropy of LaxFe1−xOy NWAs was manipulated by the length of nanowires outside the template. There is a regular change in the coercive force Hc and remanence ratio Mr/Ms with increasing length of nanowires outside the template. Therefore, the nanoarray materials with tunable magnetic anisotropy were obtained by controllable preparation, and they can be applied to high‐density magnetic memory nano‐devices. [ABSTRACT FROM AUTHOR]

Perovskite-type oxynitrides hold great potential for optical applications due to their excellent visible light absorption properties. However, only a limited number of such oxynitrides with modulated physical properties are available to date and therefore alternative fabrication strategies are needed to be developed. Here, we introduce such an alternative strategy involving a precursor microstructure controlled ammonolysis. This leads to the perovskite family member LaTa(IV)O2N containing unusual Ta4+ cations. The adjusted precursor microstructures as well as the ammonia concentration are the key parameters to precisely control the oxidation state and O:N ratio in LaTa(O,N)3. LaTa(IV)O2N has a bright red colour, an optical bandgap of 1.9 eV and a low (optically active) defect concentration. These unique characteristics make this material suitable for visible light-driven applications and the identified key parameters will set the terms for the targeted development of further promising perovskite family members. Perovskite-type oxynitrides hold great potential for optical applications due to their excellent visible light absorption properties. Here, a defined precursor microstructure is used to modulate the oxidation state of tantalum during ammonolysis leading to a bright red perovskite containing tantalum in a rare 4+ -state. [ABSTRACT FROM AUTHOR]

The work is a brief review of the current state of knowledge about high-pressure superconductors with a high value of critical temperature (Tc). The described results relate to hydrogen-rich superconductors with particular emphasis on well-known hydrogen sulfide compounds and also include newly-discovered lanthanum hydride compounds. Since in the considered systems the superconductivity is phononinduced, in theoretical predictions the Eliashberg equations formalism has been used, while some of the results were extended by including the results obtained in calculations using the density functional theory method. Theoretical predictions were compared with the results of experiments available in the literature. A holistic view of the latest results may lead the way to discover the superconductivity at room temperature. [ABSTRACT FROM AUTHOR]

The work is a brief review of the current state of knowledge about high-pressure superconductors with a high value of critical temperature (Tc). The described results relate to hydrogen-rich superconductors with particular emphasis on well-known hydrogen sulfide compounds and also include newly-discovered lanthanum hydride compounds. Since in the considered systems the superconductivity is phononinduced, in theoretical predictions the Eliashberg equations formalism has been used, while some of the results were extended by including the results obtained in calculations using the density functional theory method. Theoretical predictions were compared with the results of experiments available in the literature. A holistic view of the latest results may lead the way to discover the superconductivity at room temperature. [ABSTRACT FROM AUTHOR]

Lanthanum-doped zinc oxide (ZnO:La) thin films were deposited using a nebulizer spray technique with La concentrations 0, 1, 3 and 5 wt%. The structural, morphological and gas sensing properties were studied. All the film samples exhibit considerable ammonia sensing ability. The gas sensing results show that the ZnO:La film with 3 wt% of La doping exhibits remarkable sensing response and fast response/recovery times (39 s/11 s) for 100 ppm of NH3 at room temperature. The reasons for the enhanced sensing ability of the doped films have been addressed with the help of the underlying mechanism, atomic force microscopy (AFM) and photoluminescence (PL) results. [ABSTRACT FROM AUTHOR]

In this study, we prepared strontium-doped lanthanum ferrites with the perovskite-type structure for application as solid oxide fuel cell (SOFC) cathodes. We used the Pechini method to prepare strontium-doped lanthanum ferrites with the strontium:lanthanum molar ratios of 20:80 and 40:60. The resulting doped materials were characterized using various analytical tools. The calcination process was conducted at 450 °C because above this temperature, the stabilization of mass loss occurred and no phase transformation was observed. The X-ray diffraction results confirmed the mixing of the powder phases after the calcination process and the presence of a single powder phase in the air-sintered samples. The high-resolution transmission electron microscopy results revealed the presence of agglomerated nanoparticles smaller than 20 nm in size in the samples. The electrochemical impedance spectroscopy results revealed that the sample with 20% strontium exhibited a conductivity of 3.9 × 10−3 S cm−1 at 95 °C and activation energy of 0.37 eV. In contrast, the sample with 40% strontium exhibited a conductivity of 3.5 × 10−2 S cm−1 and activation energy of 0.29 eV. These results suggest that with an increase in the strontium content, the conductivity of the samples increased, where as the activation energy of the conduction process decreased. Therefore, the ferrites synthesized in this work are potential catalysts for SOFC cathodes. [ABSTRACT FROM AUTHOR]

We have made measurements of the de Haas-van Alphen (dHvA) effect and the magnetic susceptibility of La1-x Smx B6 for x=0, 0.05, and 0.10 and Ce1-x Cax B6 for x=0 0.01, 0.03, and 0.05 in order to see changes in the Fermi surface (FS) volume with doping using lower valence substitutions for La and Ce. The FS volume decrease in La1-x Smx B6 is found to be directly proportional to the decrease in the number of electrons contributing to the boron-based conduction band by the decrease in valence of the divalent element. Two overlapping pieces of FS in the same portion of the Brillouin zone are seen to decrease in volume to the extent that they no longer overlap. In the case of Ce1-x Cax B6 the combination of increased disorder decreasing the mean-free path due to doping and heavy effective masses results in the damping of the dHvA oscillations and no signals are observed above x=0.05. Due to the mixed valence of the Ce atoms the volume decrease is not proportional to the percent valence change. Additional magnetic-susceptibility and magnetization measurements show the changing magnetic phase diagram in Ce1-x Cax B6. In the antiferroquadrapolar state of all of the Ce1-x Cax B6 samples the near-zero applied field magnetization is seen to increase with decreasing temperature terminating in a transition to the antiferromagnetic state. © 2009 The American Physical Society.

We have made measurements of the de Haas-van Alphen (dHvA) effect and the magnetic susceptibility of La1-x Smx B6 for x=0, 0.05, and 0.10 and Ce1-x Cax B6 for x=0 0.01, 0.03, and 0.05 in order to see changes in the Fermi surface (FS) volume with doping using lower valence substitutions for La and Ce. The FS volume decrease in La1-x Smx B6 is found to be directly proportional to the decrease in the number of electrons contributing to the boron-based conduction band by the decrease in valence of the divalent element. Two overlapping pieces of FS in the same portion of the Brillouin zone are seen to decrease in volume to the extent that they no longer overlap. In the case of Ce1-x Cax B6 the combination of increased disorder decreasing the mean-free path due to doping and heavy effective masses results in the damping of the dHvA oscillations and no signals are observed above x=0.05. Due to the mixed valence of the Ce atoms the volume decrease is not proportional to the percent valence change. Additional magnetic-susceptibility and magnetization measurements show the changing magnetic phase diagram in Ce1-x Cax B6. In the antiferroquadrapolar state of all of the Ce1-x Cax B6 samples the near-zero applied field magnetization is seen to increase with decreasing temperature terminating in a transition to the antiferromagnetic state. © 2009 The American Physical Society.