Magnetotransport Properties Of La0 Research Articles

Structural, electrical, magnetic and magnetotransport properties of La0.7Ca0.18Ba0.12Mn0.95Sn0.05O3 manganite prepared with different quenching processes

Structural, electrical, magnetic and magnetotransport properties of La0.7Ca0.18Ba0.12Mn0.95Sn0.05O3 manganite prepared with different quenching processes

Asymmetric ground states in La0.67Sr0.33MnO3/BaTiO3 heterostructures induced by flexoelectric bending

Misfit strain delivered from single-crystal substrates typically modifies the ground states of transition metal oxides, generating increasing interest in designing modern transducers and sensors. Here, we demonstrate that magnetotransport properties of La0.67Sr0.33MnO3 (LSMO) films were continuously tuned by uniaxial strain produced by a home-designed bending jig. The electrical conductivity and Curie temperature of LSMO films are enhanced by bending stresses. The resistivity of u-shape bended LSMO decays three times faster than that of n-shape bended LSMO as a response to the same magnitude of strain. The asymmetric magnetic states in uniaxially strained LSMO are attributed to the dual actions of Jahn–Teller distortion and strain gradient mediated flexoelectric fields in an adjacent ferroelectric layer. These findings of multi-field regulation in a single material provide a feasible means for developing flexible electronic and spintronic devices.

Stability of charge ordering in La0.5−xHoxCa0.5MnO3 polycrystalline manganites

Magnetotransport properties of La0.5−xHoxCa0.5MnO3 (x = 0.05 and 0.1) polycrystalline samples were investigated in order to study the effect of magnetic Ho3+ ions on the stability of the charge ordering (CO) and magnetic phase coexistence in pristine La0.5Ca0.5MnO3. Our samples were synthesized by using solgel method. Temperature dependence of resistivity shows an insulating behavior with high resistivity values, confirming the presence of long-range CO. The application of 7 T magnetic field slightly reduces resistivity values and demonstrates relatively small magnetoresistance (MR) values (−MR(T) did not exceed 14% under 7 T applied field). This observation indicates that the CO in the Ho-based specimens is strong, which indicates that Ho substitution for La in La0.5Ca0.5MnO3 gives more strength to the CO.

Colossal magneto-resistive relaxation effects in La0.9Ce0.1Fe12B6

The study of the magnetic, electronic transport, and magnetotransport properties of La0.9Ce0.1Fe12B6 itinerant-electron system has been performed by combining magnetization, electrical resistivity, and magnetoresistance experiments. Along with the antiferromagnetic (AFM) ordering at TN = 35 K, two consecutive magnetic transformations, antiferromagnetic–ferromagnetic (AFM–FM) and ferromagnetic–paramagnetic (FM–PM), occur upon heating under certain magnetic field values. At fixed temperatures, it is revealed that both AFM and PM phases can be converted into the FM phase irreversibly and reversibly via a first-order metamagnetic transition associated with a large hysteresis. Below 8 K, the metamagnetic transition is discontinuous, manifesting itself by multiple sudden jumps in magnetoresistance and magnetization. A giant negative magnetoresistance effect of about −78% is found. We further demonstrate that the time dependencies of the electrical resistivity and the magnetization exhibit colossal spontaneous steps after an incubation time in conditions where both the applied magnetic field and temperature are constant. Another intriguing observation in the phase diagram is the presence of a critical point at the crossover of the three distinct PM, FM, and AFM magnetic states.

Effects of aliovalent dopants in LaMnO3: Magnetic, structural and transport properties

In this paper, we have investigated the modification in structural, magnetic, transport, and magneto-transport properties of La0.95X0.05MnO3 polycrystalline samples prepared by the citrate combustion route with doping of different valence ions (X = Ce, Dy, Er, Sr, Na and La) as well as erbium-doped La1-xErxMnO3 samples (x = 0.0, 0.05, 0.1, and 0.3). X-ray diffraction patterns measured at room temperature confirmed the single-phase perovskite hexagonal structure with R-3c space group in all of these samples, excluding the 30% Er substituted sample. The grain sizes estimated from the SEM images were found to be in a range of 1.8–3 µm for all of the sintered samples (at 1300 °C/3h), and below 100 nm for the calcined powders (at 600 °C/3h). Curie temperatures of undoped and doped LaMnO3 powder samples were observed in the range of 230–255 K, significantly higher than the reported value (~140 K) for undoped samples. The maximum saturation magnetization (at 10 K) was obtained for the undoped sample (92 emu/g) and the largest coercivity (60 Oe) was found for the 5% Er-doped LaMnO3 sample. Temperature dependence of resistivity was measured in the absence and presence of the magnetic field (5 T), and the curves suggest a metal–insulator transition. The 5% Er-doped sample exhibited insulating behaviour while the higher Er concentration (10%) doping caused the metal–insulator transition. The rich and tuneable magnetic, transport and magneto-transport properties make these samples promising candidates for biosensors, memory devices, and other technological applications.

Evolution of electrical and magnetotransport properties with lattice strain in La0.7Sr0.3MnO3 film**Project supported by the National Natural Science Foundation of China (Grant No. 10974105), the Double-Hundred Talent Plan, Shandong Province, China (Grant No. WST2018006), the Recruitment Program of High-end Foreign Experts, China (Grant Nos. GDW20163500110 and GDW20173500154), and the Top-notch Innovative Talent Program of Qingdao City, China (Grant No. 13-CX-8).

In this paper, we investigate the effects of lattice strain on the electrical and magnetotransport properties of La0.7Sr0.3MnO3 (LSMO) films by changing film thickness and substrate. For electrical properties, a resistivity upturn emerges in LSMO films, i.e., LSMO/STO and LSMO/LSAT with small lattice strain at a low temperature, which originates from the weak localization effect. Increasing film thickness weakens the weak localization effect, resulting in the disappearance of resistivity upturn. While in LSMO films with a large lattice strain (i.e., LSMO/LAO), an unexpected semiconductor behavior is observed due to the linear defects. For magnetotransport properties, an anomalous in-plane magnetoresistance peak (pMR) occurs at low temperatures in LSMO films with small lattice strain, which is caused by two-dimensional electron gas (2DEG). Increasing film thickness suppresses the 2DEG, which weakens the pMR. Besides, it is found that the film orientation has no influence on the formation of 2DEG. While in LSMO/LAO films, the 2DEG cannot form due to the existence of linear defects. This work can provide an efficient way to regulate the film transport properties.

Tuning of Al doping on martensitic-like transition in phase separated manganites La0.6Ca0.4Mn1-xAlxO3-δ

The tuning effects of Al3+ doping on the magnetic and magnetotransport properties of La0·6Ca0·4MnO3-δ have been studied by preparing series La0·6Ca0·4Mn1-xAlxO3-δ (x = 0, 0.1, 0.125 and 0.15). Al3+ doping suppresses the ferromagnetic metal phase of La0·6Ca0·4MnO3-δ by weakening the double-exchange interaction of Mn3+-O2--Mn4+, leading to a phase separation state. Al3+ doping dependent irreversible metamagnetic transitions are observed at lower temperatures, especially a martensitic-like transition appears in x = 0.125 and 0.15 system below 4.2 K. Phase diagrams of La0·6Ca0·4Mn1-xAlxO3-δ (0.1 ≤ x ≤ 0.15) in the B-T plane are presented, in which the antiferromagnetic insulator and ferromagnetic metal phases boundary is figured out. The antiferromagnetic matrix and magnetic disorders caused by the random distribution of Al3+ ions and the spontaneous oxygen vacancies grow into a pinning center to pin the Mn moments. As magnetic field is increased to the critical field, the localized magnetic moments rotate to parallel to the magnetic field direction, leading to a martensitic-like transition.

Interface driven electrical and magneto-transport properties of (100 – x)% La0.7Sr0.3MnO3– x% Paraffin wax (0 ≤ x ≤ 1) hybrid nanocomposites

We report electrical and magneto-transport properties of La0.7Sr0.3MnO3(LSMO)/Paraffin wax nanocomposites prepared through low temperature chemical pyrophoric reaction process. A core shell structure is expected to be formed having a ferromagnetic LSMO core and a spin disordered shell of paraffin wax. Enhanced charging energy due to coulomb blockade contribution with increasing paraffin wax is observed for the composites attributing enhanced intergranular distance between LSMO grains. Effective spin-polarized tunneling of conduction electrons resulting in sharp low field magnetoresistance (MR) of the composites is due to reordering of spin disorder at paraffin wax shell with magnetic field. Moreover, observation of enhanced magnetoresistive hysteresis with decrease in temperature has been attributed to increased blocked states at LSMO grain surface. Calculated surface spin susceptibility (χb) has been found to follow similar behavior of MR with temperature indicating surface magnetization dependent MR. Fitting of magnetoconductance versus field curves reveal increase of Para to ferro transition temperature, TC and χb indicate higher antiferromagnetic coupling of shell spins for composite samples than pristine LSMO above 50 K. χb also indicate systematic decrease in surface spin disorder of the composite samples with respect to pure LSMO which is expected to be due to the probable covalent bond formation between Paraffin wax molecules and surface atoms of LSMO nanoparticles.

Monovalent doping effects on the structural, magnetic and magnetotransport properties of La0.833R0.167MnO3 (R = Li+, Na+, Ag+, K+)

This work elaborates the effects of monovalent doping on the structural, magnetic and magnetotransport properties of La0.833R0.167MnO3, where R = Li+, Na+, Ag+ and K+. Rietveld refinement of XRD profiles reveal that the compounds crystallize in rhombohedral structure, with the rhombohedral distortion angle (α) exhibiting an inverse relation with A-site ionic radius (˂ rA˃). A detailed investigation on room temperature Fourier transform infrared spectra (FTIR) of samples comprehends the evolution of Mn-O bond vibrations across the metal-insulator transition temperature (Tp). Surface morphological studies done by field emission scanning electron microscopy (FESEM) confirm the presence of well grown grains in the samples. The magnetization studies on La0.833Li0.167MnO3 indicate that the sample exhibits a magnetically frustrated spin glass state with irreversible metamagnetic transition at high magnetic fields. On the other hand, Na, Ag and K doped samples exhibit a soft ferromagnetic nature, with faster saturation at lower fields. Magnetotransport studies indicate that Li doped sample possess a charge ordered state close to its spin glass transition temperature, Tg = 113 K. Double resistivity peaks exhibited by La0.833Na0.167MnO3, La0.833Ag0.167MnO3 and La0.833K0.167MnO3 are discussed based on magnetic phase separation inherent in these samples. The transport and magnetic studies of the present samples contradict the widely accepted notion that Curie temperature (Tc) and Tp in manganites closely follow ˂rA˃ values. Fitting the resistivity data of samples to various theoretical models reveal the nature of conduction mechanisms realized in different temperature regimes. High resistivity of La0.833Li0.167MnO3 signals that the charge carriers are in a highly localized state. This is attributed to its low ˂ rA˃ and the consequent structural distortions.

The consequences of growth modes on the magnetotransport properties of La0.4Pr0.3Ca0.3MnO3/LAO films

The impact of pulse repetition rate and film thickness on the magnetic, magnetoresistance (MR) and anisotropic magnetoresistance (AMR) has been investigated for La0.4Pr0.3Ca0.3MnO3 thin films grown on LaAlO3 (LAO) substrates by pulsed laser deposition technique. Change in repetition rate led to a difference in growth modes and altered the magnetic and electrical properties (MR and AMR) of thin films. The XRD results show that in the films with the thickness of 100 nm, by increasing the pulse repetition rate from 2 to 7 Hz the strain level doesn’t change, while strain significantly increased at the repetition rate of 10Hz. Analysis of transport and magnetization measurements show that at 2 and 5 Hz deposited films, the ferromagnetic metallic behavior is dominant, while in the film deposited at 10 Hz the antiferromagnetic (AFM) insulating phase increased. Moreover, with increasing strain in the thinner films (40 nm), deposited at 2 Hz, AFM phase is strengthened. Exchange bias confirms the existence of a dead layer in 100 nm film deposited at 10 Hz and 40 nm film deposited at 2 Hz. In addition, high strain in thinner films led to an enhanced Jahn-Teller coupling, so the angular momentum and spin-orbital/lattice interactions are significantly increased, which led to a lower magnetoresistance in thinner films. These results suggest that the pulse repetition rate provides an additional degree of freedom to tune magnetic and electrical properties of manganite thin films prepared by pulsed laser deposition technique.

Structural, magnetic and magnetotransport properties of La0.67Ba0.332−xRbxMnO3 perovskites prepared by flux method

Abstract We have undertaken a systematic study of the effect of Rb+ doping on the X-ray diffraction, magnetic and electric transport properties of the mixed valence perovskites La0.67Ba0.33−xRbxMnO3 ( 0 ≤ x ≤ 0.1 ), prepared by the flux technique. X-ray diffraction and structure refinement showed the formation of single-phase compositions with rhombohedral symmetry with R 3 ¯ c space group. Magnetization measurements in a magnetic field of 0.05 T confirm a transition from ferromagnetic (FM) to paramagnetic (PM) phase with increasing temperature. The Curie temperature TC decreases from 340 K (x = 0) to 296 K (x = 0.1). The decrease of Tc can be explained by the M n 4 + content increase. Upon Rb doping, the temperature TM-Sc decreases, in accordance with the evolution of TC values (from 340 to 296 K). The electrical resistivity concluded that the metallic part (below TM-Sc) can be explained by the following equation ρ ( T ) = ρ 0 + ρ 2 T 2 + ρ 4.5 T 4.5 , signifying the importance of the domain boundary / grain, combination of electron-magnon, electron-electron and electron phonon scattering processes. At higher temperature (T > TM-Sc) the semiconducting regime, the adiabatic small polarons hopping mechanism (ASPH) was found to fit well.

Assessment of the relationship between magnetotransport and magnetocaloric properties in nano-sized La0.7Ca0.3Mn1−xNixO3 manganites

The effect of Ni2+ substitution on the magneto-transport properties and the concomitant relationship with the magnetocaloric function of nano-sized La0.7Ca0.3Mn1−xNixO3 (x = 0, 0.02, 0.07, and 0.10) perovskite manganites are reported. All the samples were synthesized using the auto-combustion method. X-ray diffraction analysis studies confirmed the phase purity of the synthesized samples. The substitution of Mn3+ ions with Ni2+ ions in the La0.7Ca0.3MnO3 lattice was also verified using this technique. Rietveld analysis indicated that the volume of the unit cell increased with increasing Ni2+ content. Zero-field-cooled and field-cooled magnetization showed that all samples underwent a paramagnetic-ferromagnetic phase transition, which was concomitant with a metal-insulator transition. A small deviation between the zero-field-cooled and field-cooled magnetization curves was observed when the measurements were carried out in a field of 1000 Oe. The Curie temperature decreased systematically from 264 K for x = 0 to 174 K for x = 0.10. Probably the doping at the Mn3+ sites with Ni2+ ions in the La0.7Ca0.3MnO3 lattice weakened the Mn3+-O-Mn4+ double exchange interaction, which led to a decrease in the transition temperature. The metal-insulator transition also shifted to lower temperatures upon Ni2+ substitution, and the value of the resistivity increased. Different conduction mechanisms were found in different temperature regions. Important physical parameters such as the polaron activation energy were obtained from the fit of the models to the experimental data. Arrot’s plots revealed a second-order nature of the magnetic transition for all the samples, which was also confirmed by Landau’s theory and universal curves. The second-order character of the magnetic phase transition observed in the pristine La0.7Ca0.3MnO3 sample may be attributed to effects of the downsizing of the particle. Interestingly, a notable increase in the value of the magnetic entropy change was observed at Ni2+ doping levels as low as 2%. The magnetoresistance underwent a great change near the magnetic transition temperature, suggesting a close relationship between the magnetocaloric effect and magnetotransport properties in La0.7Ca0.3MnO3 manganites. Such behavior can be attributed to the spin order/disorder feature, which plays a crucial role in both effects. On the other hand, the value of the magnetoresistance of the pristine La0.7Ca0.3MnO3 sample increased upon Ni2+ doping, which is probably related to the downsizing of the particles.

Grain Size Effect on Electrical and Magnetotransport Properties of La0.67Ca0.33MnO3 synthesized via Sol-Gel Method

The effect of grain size on electrical resistivity and magnetoresistance (MR) effect on La0.67Ca0.33MnO3 prepared via sol-gel method was reported with different sintering temperature starting from 600°C to 1200°C. X-ray diffraction (XRD) patterns show that La0.67Ca0.33MnO3 was in single phase and had orthorhombic structure with space group Pbnm (62). The crystallite size as well as particle size show strong dependence on sintering temperature (Ts). The metal-insulator transition (TMI) and the magnitude of magnetoresistance are significantly influenced by the effective grain boundaries in LCMO polycrystalline. The TMI and its resistivity increases as the grain size and crystallite size increases (Ts increase). The highest low-field magnetoresistance (LFMR), which extrinsic percentage of MR is more dominant, observed in LC-SG8 (-12.89%) with nano-sized distribution that showing double crystallite structure. However, the highest CMR is found in LC-SG10 (-23.48%) at 80 K with 1 Tesla. These percentage variations of MR for all samples were influenced by the grain size and crystallite size variations which consequently affect the spin polarized-tunneling scattering at the grain boundary layer.

Magnetic Structure and Magnetotransport Properties of La0.7Sr0.3Mn1 – xNi x O3

La0.7Sr0.3Mn1 – xNi x O3 (0.12 ≤ x ≤ 0.35) compositions have been studied using neutron diffraction, magnetometry, and measurements of magnetotransport properties. At temperatures of 5–300 K, these compounds were found to have a rhombohedral crystal structure. The substitution of nickel for manganese has been shown to result in a decrease in the Curie temperature from 278 K (х = 0.12) to 60 K (х = 0.3); in this case, the spontaneous magnetization of the compositions decreases to zero (x = 0.33). The magnetoresistive effect for the semimetals with 0.12 ≤ x < 0.18 increases near the Curie temperature, whereas the magnetoresistance of semiconducting compositions with х ≥ 0.2 progressively decreases as the temperature increases. For compositions with х ≥ 0.25, an antiferromagnetic G-type component has been found by neutron diffraction, the Neel temperature of which reaches 260 K (at х = 0.35). The study of the La1–ySr y Mn0.65Ni0.35O3 (y ≤ 0.3) system showed that the content of ferromagnetic component decreases with increasing Sr content. It has been inferred that the antiferromagnetism of the compositions with х > 0.25 is due to the strong negative exchange interactions Ni2+–О–Ni2+ and Mn4+–О–Mn4+ and the absence of ionic order. The obtained data have been used to construct the magnetic phase diagram of the La0.7Sr0.3Mn1–xNi x O3 (0.12 ≤ x ≤ 0.35) system.

Effect of charge ordering and phase separation on the electrical and magnetoresistive properties of polycrystalline La0.4Eu0.1Ca0.5MnO3

We have investigated the effect of charge ordering and phase separation on the electrical and magnetotransport properties of La0.4Eu0.1Ca0.5MnO3 polycrystalline sample. Temperature dependence of resistivity shows a metal–insulator transition at transition temperature Tρ. A hysteretic behavior is observed for zero field resistivity curves with Tρ = 128 K on cooling process and Tρ = 136 K on warming process. Zero field resistivity curves follow Zener polynomial law in the metallic phase with unusual n exponent value ∼9. Presence of resistivity minimum at low temperatures has been ascribed to the coulombic electron–electron scattering process. Resistivity modification due to the magnetic field cycling testifies the presence of the training effect. Magnetization and resistivity appear to be highly correlated. Magnetoresistive study reveals colossal values of negative magnetoresistance reaching about 75% at 132 K under only 2T applied field. Colossal values of magnetoresistance suggest the possibility of using this sample for magnetic field sensing and spintronic applications.

Magnetic and magnetoresistance properties of La0.7Sr0.3(Mn,Сo)O3

Magnetic and magnetotransport properties of La0.7Sr0.3Mn1−xCoxO3 ceramics have been investigated by neutron powder diffraction, magnetization and electrical measurements. It is shown that substitution by cobalt ions leads to a decrease of magnetic transition temperature down to 140K for the compound with x = 0.33. The compounds with cobalt content 0.4 < x < 0.6 are characterized by a presence of small ferromagnetic component due to exchange interactions between cobalt and manganese ions with maximal transition temperature of about 190K observed for x = 0.5. Further increase of the dopant concentration diminishes ferromagnetic interactions. An evolution of electronic configuration of manganese and cobalt ions upon chemical substitution as well as related changes in the exchange interactions which determine the type of the magnetic state are discussed. Based on the neutron diffraction results and magnetometry data the preliminary magnetic phase diagram has been constructed.

Structure defects, phase transitions, magnetic resonance and magneto-transport properties of La0.6–xEuxSr0.3Mn1.1O3–δ ceramics

Structure and its defects, magnetic resonance and magneto-transport properties of La0.6–xEuxSr0.3Mn1.1O3–δ magnetoresistive ceramics were investigated by x-ray diffraction, thermogravimetric, resistance, magnetic, 55Mn NMR and magnetoresistance methods. It was found that isovalent substitution of lanthanum by europium A-cation of a smaller ionic radius increases the structural imperfection and leads to a symmetry change from the rhombohedrally distorted perovskite structure of R3¯c symmetry to the pseudocubic type. It was shown that the real structure contains anionic and cationic vacancies, the concentrations of which increases with the Eu concentration and the sintering temperature tann. A decrease in the temperature of the metal–semiconductor Tms and ferromagnetic–paramagnetic TC phase transitions as well as an increase in the resistivity ρ and the activation energy Ea with increasing x are due to an increase in vacancy concentration, which weakens the high-frequency electron double exchange Mn3+ ↔ O2– ↔ Mn4+. The crystal structure of the compositions x = 0 and 0.1 contains nanostructured planar clusters, causing anomalous magnetic hysteresis at T = 77 K. Broad asymmetric 55Mn NMR spectra confirm high-frequency electron double exchange Mn3+(3d4) ↔ O2–(2p6) ↔ Mn4+(3d3) and indicate inhomogeneity of the manganese environment due to the surrounding ions and vacancies. The effective local fields of the hyperfine interaction HHF at 55Mn nuclei have been calculated by decomposing asymmetric NMR spectra into three Gaussian components. The constructed experimental phase diagram of the magnetic and conducting states of the La0.6–xEuxSr0.3Mn1.1O3–δ ceramics revealed strong correlation between the composition, structural imperfection, phase state, and magnetotransport properties of rare-earth manganites.

Magneto-transport properties of La0.75Ca0.15Sr0.1MnO3 with YBa2Cu3O7–δ addition

We report the structural, magnetic, electrical and magentoresistance properties of (La0.75Ca0.15Sr0.1MnO3)1−x(YBa2Cu3O7−δ)x (with x=0, 0.025, 0.05, 0.075, 0.1, 0.2, and 0.3) composites synthesized through sol–gel method. The powder X-ray diffraction patterns indicate no evidence of reaction between La0.75Ca0.15Sr0.1MnO3 (LCSMO) and YBa2Cu3O7−δ (YBCO). The addition of YBCO induces a reduction of the total magnetization while the Curie temperature remains almost constant (∼312K). The behavior of the electrical resistivity evolves differently depending on the doping level. Above the paramagnetic–insulating transition temperature the resistivity data were best-fitted by using the adiabatic small polaron and variable range hopping models. Ferromagnetic–metallic regime in the composites seems to emanate from the electron–phonon or/and electron–magnon scattering processes. With increasing the YBCO doping content (until x=0.1), the positive magnetoresistance (MR) of YBCO phase dominates the negative MR of LCSMO one, which gives rise to the decreasing of MR of the composites.

Investigation of magnetic interactions, electrical and magneto-transport properties in Ga-substituted La0.4Bi0.6MnO3 perovskite manganites

We report on magnetic, electrical and magneto-transport properties in La0.4Bi0.6Mn1−xGaxO3 (with x=0.05 and x=0.1) samples. The phase purity and microstructural analysis of the samples have been carried out using X-ray diffraction and scanning electron microscopy technique. From the magnetization data, the studied samples show paramagnetic to ferromagnetic transition followed with glassy behavior at low temperatures. Frequency dependent ac susceptibility measurements reveal dynamic fluctuations due to cooperative interactions between antiferromagnetic domain pinning effects giving rise to glassy behavior in the studied samples. Electrical resistivity measurements suggest semiconducting behavior for the studied samples in the measured temperature range (100–300K). Our study reveals that resistivity data for T≤ (θD/2, the Debye temperature) follow power law and for T>θD/2 Shklovskii-Efros variable range hopping transport mechanism. The MR% vs. magnetic field has been studied to understand the simultaneous behavior of FM and insulating nature around T=100K existing in the samples.

Impact of CuO phase on magnetocaloric and magnetotransport properties of La0.6Ca0.4MnO3 ceramic composites

We report the magnetocaloric and magneto-transport properties of the perovskites manganites composites (La0.6Ca0.4MnO3)/x(CuO) (LCMO/CuO) (x = 0.00, 0.07 and 0.18) synthesized by solid-state reaction method. X-ray diffraction (XRD) study was employed to confirm the formation of both the phases in composites. The results of magnetic measurements indicate that CuO mainly segregates at the grain boundaries of LCMO. Arrott analysis and master curve behavior reveal second order of magnetic phase transition in the composite samples. Magnetic entropy change increases with increasing CuO content and a maximum of 3 J/kg.K at 2 T has been observed in LCMO/(0.18)CuO sample. The detailed electrical characterizations showed that with increasing the CuO doping level, Tρ shifts to a lower temperature and the resistivity decreases. The low field magnetoresistance (LFMR) results from spin-polarized tunneling. However, around room temperature, the enhanced MR of the composites is caused by magnetic disorder. MR has been found to reach a maximum value of 30% at 2 T applied field with 18% CuO addition. The enhanced MR and ΔSM of these composites make them attractive for potential applications.