Specific Heat Anomalies Research Articles

Transient heat-flux method for measuring heat capacity: examples from Cu and VO2

Many quantum materials undergo phase transitions above room temperature. However, thermodynamic evidence of these phase transitions is relatively scarce. For instance, detailed specific heat anomalies have rarely been reported for the transitions. In addition to considering intrinsic factors that obscure the thermodynamic manifestation of relevant degrees of freedom, it is also important to revisit measurement techniques based on firmly established physical principles. In this study, we introduce a transient heat-flux method for measuring heat capacity of solids, and report a specific heat anomaly in VO2, along with the reproduction of the standard specific heat capacity data of Cu. At present, our method is capable of measuring heat capacities ranging from 1 J/mol⋅K to 400 J/mol⋅K with an uncertainty of 5 % across a temperature range from room temperature to 100 °C.

First-order transition under a magnetic ordered state in SmPtSi2

We have synthesized polycrystalline and single-crystalline samples of SmPtSi2, and measured their resistivity, specific heat, magnetization, and Seebeck coefficient. The existence of two magnetic phase transitions has been confirmed, one at T H = 8.6 K and the other T L = 5.6 K. A hump-type anomaly in resistivity, a lambda-type anomaly in specific heat, a downward bend in magnetization, and a semiconductor-like increase in the Seebeck coefficient were observed at T H, indicating an antiferromagnetic transition accompanied by a gap opening on the Fermi surface. In contrast, a sharp drop in resistivity, a sharp spike in specific heat, and a drop in magnetization were observed at T L. The Seebeck coefficient showed metallic temperature dependence below T L. With increasing pressure, T H and T L shifted to higher temperatures. The transition at T L was no longer observed at pressures above 1.5 GPa. These findings suggest that the transition at T L is a transition from an antiferromagnetic ordered state with the gap on the Fermi surface to a different antiferromagnetic state.

Observation of Magnetic Field‐Induced and Partially Switchable Electric Polarization in Spin‐Chain FePbBiO4

AbstractThe linear magnetoelectric (ME) characteristics of a quasi‐1D spin‐chain compound, FePbBiO4, are reported. Two distinct antiferromagnetic (AFM) orders occurring at ≈23 K (TN1) and 12 K (TN2) are verified using magnetization, specific heat, and conspicuous dielectric (ε′) anomalies. A striking observation is that no pyrocurrent (Ipy) is detected in the absence of magnetic field (H); however, H‐induced ferroelectric polarization (P) at TN1 and P unexpectedly partially switches or reverses below TN2 as reproduced by applying positive and negative electric fields (E). The resulting magnetic field and temperature (H‐T) phase diagram illustrates T‐dependent H‐induced spin reorientation and electric P. The interaction between T, H, spin dynamics, and lattice structures is pivotal and is qualitatively discussed and proposed as an explanation for the observed ME nature.

Magnetic and electrical transport properties in GdAlSi and SmAlGe

Abstract In this work, we conduct a detailed examination of the magnetic and electrical transport properties in GdAlSi and SmAlGe crystals, which possess a LaPtSi-type structure (space group I41 md). The magnetic susceptibility data unambiguously reveal magnetic ordering below a characteristic transition temperature (T N ). For GdAlSi, a hysteresis loop is observed in the magnetization and magnetoresistance curves within the ab plane when the magnetic field is applied below T N , which is around 32 K. Notable specific heat anomalies are detected at 32 K for GdAlSi and 6 K for SmAlGe, confirming the occurrence of magnetic transitions. Besides, the extracted magnetic entropy at high temperatures is consistent with the theoretical value of Rln(2J+1) for J = 7/2 in Gd3+ and J = 5/2 in Sm3+, respectively. SmAlGe also exhibits Schottky-like specific heat contributions. Additionally, both GdAlSi and SmAlGe exhibit positive magnetoresistance and a normal Hall effect.

Underpinnings behind the magnetic order-to-disorder transition and property anomaly of disproportionated insulating samarium nickelate

Perovskite nickelates (RNiO3), as benchmark materials for exploring underlying physics of phase transitions in strong correlated systems, are well-known for their rich structural characteristics and physicochemical properties. Understanding phase transition from the spin-ordered antiferromagnetic (AFM) state to the spin-disordered paramagnetic (PM) state of RNiO3 requires accurate models at finite temperatures. Here, we investigate the underpinning physics behind the property anomaly and AFM-to-PM transition in samarium nickelate (SmNiO3) using a thermodynamic zentropy approach, which depicts the temperature-dependent total entropy for a system of interest via a nested formula through integration of quantum mechanics and statistical mechanics. The SmNiO3 displays the ground-state of AFM insulator as well as the PM metal and PM insulator at elevated temperatures. It turns out that the magnetic configurational entropy induced by competition among different spatially fluctuating polymorphous spin configurations, contributes to the specific-heat anomaly and the phase transition of SmNiO3 from AFM to PM state. The predicted Néel temperature of 241±25 K for SmNiO3 is in satisfactory agreement with the experimental value. Unlike empirical interpretations in literature, the present work indicates that the magnetic order-to-disorder transition in SmNiO3 is associated with the magnetic configurational entropy due to thermal mixture of multiple spin configurations at elevated temperatures, which can be quantitively captured by the first-principles based thermodynamic zentropy approach.

Magnetic frustration in rare-earth zirconates A2Zr2O7, the case of laser heated pedestal method synthesised A = Er, Tm, Yb, and Lu single crystals

Heavy rare-earth A2Zr2O7 zirconates have been studied for their high application potential, including thermal barrier coating, radiation waste storage, or solid oxide fuel cells. However, previous investigations have focused mostly on the high-temperature properties of polycrystalline samples. The low-temperature properties, important for a full understanding of these materials, remains understudied. We have newly synthesised good-quality single crystals of A2Zr2O7 with A = Er, Tm, Yb, and Lu using the laser heated pedestal method and have characterised them by means of X-ray diffraction, magnetisation, and specific heat measurements. The first three members crystallise in a cubic disordered defect-fluorite structure. Lu2Zr2O7 adopts lower-symmetry rhombohedral structure. Similar magnetic properties of all magnetic zirconates were observed at low temperature. In the unperturbed paramagnetic state, they follow the Curie-Weiss law with an effective magnetic moment close to the respective A3+ free ions. The negative paramagnetic Curie-Weiss temperature, in the case of A = Yb member highly negative, strongly suggests an antiferromagnetic ordering in the compounds. Below 30 K, the magnetic response becomes non-linear in the applied magnetic field, suggesting magnetic correlations between rare-earth moments or/and crystal field effects. Finally, at lowest measured temperature, Er2Zr2O7 and Yb2Zr2O7 members reveal a well-pronounced anomaly in specific heat at 0.9 and 1.5 K, respectively. The specific heat anomaly shifts to higher temperature in an applied magnetic field, suggesting ferromagnetic correlations – in contradiction to the negative Curie-Weiss temperature. We discuss these observations in the framework of freezing of magnetic moments on a disordered geometrically frustrated lattice. In contrast, the low-temperature properties of Tm2Zr2O7 are dictated mostly by its crystal electric field; a crystal-field-singlet ground state which does not provide degrees of freedom for a spin-freezing is proposed. No clear low-temperature anomaly in specific heat is observed down to 0.4 K for the A = Tm member. Lu2Zr2O7 does not bear any magnetic moment, therefore no magnetic signal was observed in any measured data. The results are discussed in the framework of heavy rare-earth A2B2O7 oxides and other magnetically frustrated systems.

Crystal structure of KMnPO4F with short- and long-range order inside the layered magnetic system.

Potassium manganese fluoride phosphate, KMnPO4F, has been obtained through mild hydrothermal synthesis and characterized by scanning electron microscopy, microprobe analysis and X-ray diffraction. The compound possesses an orthorhombic symmetry and chiral space group P212121 with a = 4.7884(2), b = 9.0172(4), c = 9.5801(4) Å, and Z = 4. Its crystal structure is composed of Mn3+O4F square pyramids sharing vertices with PO4 tetrahedra. This anionic framework is neutralized by K+ cations. As the temperature decreases, a short-range correlation state (Tmax ∼ 35 K) of KMnPO4F is formed, followed by the establishment of antiferromagnetic (AFM) long-range order at TN = 25 K. The latter is marked by sharp λ-type anomalies in both Fisher's specific heat d(χ‖T)/dT and heat capacity Cp. Pulsed magnetic field measurements on the single crystals identify the a axis as the easy magnetic axis and reveal a spin-flop transition at μ0Hspin-flop = 19 T. Density functional theory indicates that in variance with the three-dimensional network of KMnPO4F, it is a two-dimensional Ising magnetic system represented by buckled layers of integer spins S = 2 of Mn3+ ions. The strongest AFM exchange interaction, J1 ∼ -13 K, couples Mn3+ ions into linear chains running along the a axis. The chains themselves are ferromagnetically connected (J3 ∼ -4 K) within the ab plane. The interplane AFM exchange interaction (J2 ∼ -1 K) is weak and frustrated.

Calorimetric evidence for two phase transitions in Ba1−xKxFe2As2 with fermion pairing and quadrupling states

Materials that break multiple symmetries allow the formation of four-fermion condensates above the superconducting critical temperature (Tc). Such states can be stabilized by phase fluctuations. Recently, a fermionic quadrupling condensate that breaks the Z2 time-reversal symmetry was reported in Ba1−xKxFe2As2. A phase transition to the new state of matter should be accompanied by a specific heat anomaly at the critical temperature where Z2 time-reversal symmetry is broken ({T}_{{{{{{{{rm{c}}}}}}}}}^{{{{{{{{rm{Z2}}}}}}}}} , > , {T}_{{{{{{{{rm{c}}}}}}}}}). Here, we report on detecting two anomalies in the specific heat of Ba1−xKxFe2As2 at zero magnetic field. The anomaly at the higher temperature is accompanied by the appearance of a spontaneous Nernst effect, indicating the breakdown of Z2 symmetry. The second anomaly at the lower temperature coincides with the transition to a zero-resistance state, indicating the onset of superconductivity. Our data provide the first example of the appearance of a specific heat anomaly above the superconducting phase transition associated with the broken time-reversal symmetry due to the formation of the novel fermion order.

Strong spin frustration and magnetism in kagomé antiferromagnets LnCu3(OH)6Br3 (Ln = Nd, Sm, and Eu)

To study the effects of lanthanide ions on the geometrically frustrated antiferromagnets and their magnetic properties, we grew high-quality single crystals of LnCu3(OH)6Br3 (Ln = Nd, Sm, and Eu) by hydrothermal method and studied their crystal structures and magnetic properties. The refinements of the crystal structure referred to the powder x-ray diffraction data show that LnCu3(OH)6Br3 adopt a Kapellasite-type layer structure, which is isostructural to their chlorine analogue. Magnetic susceptibilities demonstrate that LnCu3(OH)6Br3 have strong antiferromagnetic coupling and a pronounced magnetic frustration effect. Magnetization measurements indicate canted antiferromagnetic ordering of Cu2+ ions around 16 K within the kagomé plane and weak ferromagnetic coupling. Moreover, shoulder-like anomalies in specific heat around 16 K could be a signature of emergent of magnetic ordering. The low-temperature negative magnetization and specific heat of LnCu3(OH)6Br3 (Ln = Nd, Sm, and Eu) indicate that Ln 3+ ions induce more exotic magnetic ground state properties.

Influence of crystalline electric field on the magnetic properties of CeCd3X3(X=P,As)

CeCd$_3$P$_3$ and CeCd$_3$As$_3$ compounds adopt the hexagonal ScAl$_3$C$_3$-type structure, where magnetic Ce ions on a triangular lattice order antiferromagnetically below $T_\text{N} \sim$0.42~K. Their crystalline electric field (CEF) level scheme has been determined by fitting magnetic susceptibility curves, magnetization isotherms, and Schottky anomalies in specific heat. The calculated results, incorporating the CEF excitation, Zeeman splitting, and molecular field, are in good agreement with the experimental data. The CEF model, with Ce$^{3+}$ ions in a trigonal symmetry, explains the strong easy-plane magnetic anisotropy that has been observed in this family of materials. A detailed examination of the CEF parameters suggests that the fourth order CEF parameter $B_{4}^{3}$ is responsible for the strong CEF induced magnetocrystalline anisotropy, with a large $ab$-plane moment and a small $c$-axis moment. The reliability of our CEF analysis is assessed by comparing the current study with earlier reports of CeCd$_{3}$As$_{3}$. For both CeCd$_{3}X_{3}$ ($X$ = P and As) compounds, less than 40 \% of $R\ln(2)$ magnetic entropy is recovered by $T_\text{N}$ and full $R\ln(2)$ entropy is achieved at the Weiss temperature $\theta_{p}$. Although the observed magnetic entropy is reminiscent of delocalized 4$f$-electron magnetism with significant Kondo screening, the electrical resistivity of these compounds follows a typical metallic behavior. Measurements of thermoelectric power further validate the absence of Kondo contribution in CeCd$_{3}X_{3}$.

Absence of Spin Frustration in the Kagomé Layers of Cu2+ Ions in Volborthite Cu3V2O7(OH)2·2H2O and Observation of the Suppression and Re-Entrance of Specific Heat Anomalies in Volborthite under an External Magnetic Field

We determined the spin exchanges between the Cu2+ ions in the kagomé layers of volborthite, Cu3V2O7(OH)2·2H2O, by performing the energy-mapping analysis based on DFT+U calculations, to find that the kagomé layers of Cu2+ ions are hardly spin-frustrated, and the magnetic properties of volborthite below ~75 K should be described by very weakly interacting antiferromagnetic uniform chains made up of effective S = 1/2 pseudospin units. This conclusion was verified by synthesizing single crystals of not only Cu3V2O7(OH)2·2H2O but also its deuterated analogue Cu3V2O7(OD)2·2D2O and then by investigating their magnetic susceptibilities and specific heats. Each kagomé layer consists of intertwined two-leg spin ladders with rungs of linear spin trimers. With the latter acting as S = 1/2 pseudospin units, each two-leg spin ladder behaves as a chain of S = 1/2 pseudospins. Adjacent two-leg spin ladders in each kagomé layer interact very weakly, so it is required that all nearest-neighbor spin exchange paths of every two-leg spin ladder remain antiferromagnetically coupled in all spin ladder arrangements of a kagomé layer. This constraint imposes three sets of entropy spectra with which each kagomé layer can exchange energy with the surrounding on lowering the temperature below ~1.5 K and on raising the external magnetic field B. We discovered that the specific heat anomalies of volborthite observed below ~1.5 K at B = 0 are suppressed by raising the magnetic field B to ~4.2 T, that a new specific heat anomaly occurs when B is increased above ~5.5 T, and that the imposed three sets of entropy spectra are responsible for the field-dependence of the specific heat anomalies.

Abnormal specific heat at low temperatures and transport properties in Mg-Cu-Ag-Gd bulk metallic glass

We report the pronounced low-temperature specific-heat Cp anomalies in the Mg59.5Cu22.9Ag6.6Gd11 bulk metallic glass (BMG). The extrapolated electron's temperature coefficient γ0K is up to 681.8 mJ/(mol-Gd⋅Κ2) at 0 K, which is a heavy-fermion-like behavior. The low temperature specific heat indicates an enhancement of the conduction-electron effective mass m∗ below 7.5 K, suggesting that the Mg59.5Cu22.9Ag6.6Gd11 BMG is not free-electron-like solid. The excess specific heat in the Mg-based BMG is interpreted with tunneling states and spin glass state (magnetism) which are determined by subtracting electrons' and phonons' contribution to the specific heat below 12 K. The Boson peak (BP) temperature is located at 27 K, which is much higher than the reported values of other BMGs. And, a BP height of 0.047 mJ/(mol·K4) is obtained due to reduced free volume during copper mold casting with a slow cooling rate. The electrical resistivity was also investigated between 2 and 300 K, which has a negative temperature coefficient of resistivity (TCR) below 35 K (Kondo temperature, TK) and a positive value of 3.9 × 10−4/K above 35 K. There is a minimum at about 35 K for the electrical resistivity, which can be explained by the Kondo effect. For the resistivity above 35 K, it can be explained by the Faber-Ziman model due to the T-dependence change of structure factor.

Specific Heat of the Kagome Antiferromagnet Herbertsmithite in High Magnetic Fields

Measuring the specific heat of herbertsmithite single crystals in high magnetic fields (up to $34$ T) allows us to isolate the low-temperature kagome contribution while shifting away extrinsic Schottky-like contributions. The kagome contribution follows an original power law $C_{p}(T\rightarrow0)\propto T^{\alpha}$ with $\alpha\sim1.5$ and is found field-independent between $28$ and $34$ T for temperatures $1\leq T\leq4$ K. These are serious constrains when it comes to replication using low-temperature extrapolations of high-temperature series expansions. We manage to reproduce the experimental observations if about $10$ % of the kagome sites do not contribute. Between $0$ and $34$ T, the computed specific heat has a minute field dependence then supporting an algebraic temperature dependence in zero field, typical of a critical spin liquid ground state. The need for an effective dilution of the kagome planes is discussed and is likely linked to the presence of copper ions on the interplane zinc sites. At very low temperatures and moderate fields, we also report some small field-induced anomalies in the total specific heat and start to elaborate a phase diagram.

Small-moment antiferromagnetic ordering in single-crystalline La2Ni7

Single crystals of La2Ni7 have been grown out of a binary, La-Ni melt. Temperature dependent, zero magnetic field, specific heat, electrical resistivity, and low field magnetization measurements indicate that there is a series of antiferromagnetic phase transitions at T1 = 61.0 \pm 0.2 K, T2 = 56.5 \pm 0.2 K and T3 = 42.2 \pm 0.2 K. The three specific heat anomalies found at these temperatures qualitatively have very small entropy changes associated with them and the anisotropic M(H) data saturate at ~ 0.12 {\mu}B/Ni; both observations strongly suggesting the AFM order is associated with very small, itinerant, moments. Anisotropic, H||c and H{\perp}c, {\rho}(H) and M(H) isotherms as well as constant field, {\rho}(T) and M(T) sweeps manifest signatures of multiple phase lines and result in H-T phase diagrams that are clearly anisotropic. Analysis of M(T) and M(H) data allow for the identification of the two lower temperature magnetically ordered states as antiferromagnetically ordered, with the moments aligned along the crystallographic c-axis, and the higher temperature, T2 < T < T1, state as having a finite ferromagnetic component. In addition, the metamagnetic transition at low temperatures, for H applied along the crystallographic c-axis (H||c) appears to be a near classic example of a spin-flop transition, resulting in a field stabilized antiferromagnetic state with the moments ordered perpendicular to the c-axis. Although the small moment ordering, and existence of multiple phase transitions in field and temperature, suggesting an energetic proximity of these states, could foretell a degree of pressure sensitivity, our measurements of R(T) for applied pressures up to 2.0 GPa indicate that there is very little pressure dependence of T1, T2 and T3.

Enhanced superconductivity with possible re-appearance of charge density wave states in polycrystalline Cu1-xAgxIr2Te4 alloys

In this study, we determined the effect of doping with the noble metal Ag on CuIr2Te4 superconductors. Based on the resistivity, magnetization, and heat capacity, we explored the changes in the superconductivity (SC) and charge density wave (CDW) for Cu1-xAgxIr2Te4 (0 ≤ x ≤ 1) as a function of isoelectric substitution (Cu/Ag). We assessed a complete set of competing states from suppressed CDW in the low doping region to superconductor in the middle doping region and re-entrant CDW in the high doping region, thereby obtaining an electronic phase diagram, where the superconducting dome was near bipartite CDW regions with a maximum superconducting temperature (Tc) of about 2.93 K at an Ag doping level of 12%. The lower Hc1 and upper Hc2 critical magnetic fields were determined for some representative samples in the Cu1-xAgxIr2Te4 series based on magnetization and resistivity measurements, respectively. We showed that Hc1 decreased whereas Hc2 increased as the doping content increased. The specific heat anomalies at the superconducting transitions ΔCel/γTc for representative samples comprising Cu0.92Ag0.08Ir2Te4, Cu0.88Ag0.12Ir2Te4, and Cu0.85Ag0.15Ir2Te4 were approximately 1.40, 1.44, and 1.42, respectively, which are all near the Bardeen-Cooper-Schrieffer (BCS) value of 1.43 and they indicate bulk SC in these compounds.

The magnetic behaviour of Dy2Ir2O7 – Beyond the mean field approximation

The magnetic properties of pyrochlore iridate Dy2Ir2O7 prepared by CsCl flux method were investigated by means of heat capacity and magnetization measurements. The low temperature behaviour was confirmed to be consistent with previously published results, whereas the high temperature data and their analysis are presented for the first time. The bifurcation of zero field-cooled and field-cooled magnetization curves coincides well with the onset of the anomaly in specific heat pointing to an ordering of the iridium sublattice. We confront the previously determined Dy3+ CF scheme with our high-temperature magnetization and specific heat data. The difference between calculations and experimental data, represented by 20 K specific heat anomaly, suggests the behaviour beyond the mean field approximation. The Dy2Ir2O7 differs from the rest of the heavy rare-earth pyrochlore iridates, where the mean field approximation constitutes an adequate description. The deeper understanding of the Dy2Ir2O7 magnetic behaviour requires, among others, also the phonon spectra studies.

Absence of long-range magnetic order in lithium-containing honeycombs in the Li–Cr–Sb(Te)–O phases

Li3((LiCr)(Te/Sb))O6 compounds where Cr atoms along with Li and Te or Sb are part of a honeycomb and are studied using magnetic susceptibility, specific heat, x-ray photoelectron spectroscopy and neutron diffraction. The oxides stoichiometries as determined from the neutron diffraction studies are Li4.47Cr0.53TeO6 and Li3.88Cr1.12SbO6 with a stable oxidation state of +3 for Cr. Both the compounds crystallize in space group C2/m with intermixing of cations at the 4g sites leaving the 2a sites preferentially for Te or Sb. Again, the Li+ ions alone predominantly occur in the interlayer sites. Both the compounds show a broad anomaly in specific heat at 8 K, which is robust against 8 T. A corresponding anomaly is absent in the magnetic susceptibility but recovers from its derivative, dχ(T)/dT. We ascertain the magnetic anomaly temperatures (T a ) of Li4.47Cr0.53TeO6 and Li3.88Cr1.12SbO6 as 5.9 K and 6.7 K respectively from specific heat. Although the physical properties indicated a low temperature anomaly, neutron diffraction data did not reveal a magnetic signal or a structural anomaly down to 1.5 K. This rules out a conventional long-range ordered magnetic ground state in either compounds. Combining the results from specific heat, neutron diffraction and electron paramagnetic resonance, we put forth a scenario of depleted honeycomb lattice of Cr3+ with predominant short-range magnetic correlations as the magnetic ground states of the title compounds.

Specific-Heat Anomaly of the Kagomé-Lattice Ising Model in a Magnetic Field

The properties of the kagome-lattice Ising model in an external magnetic field B have not been known well. The specific-heat anomaly of the kagome-lattice Ising model in an external magnetic field is investigated based on the enthalpy fluctuation. As the magnetic field increases, the specific heat maximum decreases, but it approaches non-zero value for large magnetic field. In particular, the asymptotic line to the specific-heat maximum temperature Th(B) follows Th(B) = 0.8335565596(B + 4). The well-known experimentalist formula Tp(B) = 0.8335565596B for paramagnet shows the same slope as the asymptotic line Th (B) of the kagome-lattice Ising model in an external magnetic field.

Structural Nature of Boson Peak and Low‐Temperature Heat Excess in As2S3 Glass

Comparative analysis of experimentally measured Raman spectra of crystalline (c), glassy (g), and powdered c‐As2S3 samples is performed based on vibrational modes of As6S6+6/2 ring‐like nanoclusters being fully (“rigid”) or partially (“soft”) interconnected with the glassy matrix, calculated using density functional theory (DFT). Although good agreement is found in the 100–500 cm−1 spectral range, the DFT simulations show additional super‐low frequency modes of “soft” rings at wavenumbers being significantly lower than the “rigid” ring's vibrational band at 26 cm−1. Broadening of the relatively narrow low‐frequency band of “rigid” clusters is found to be dependent on the number of interconnections of “soft” clusters with the glassy matrix, demonstrating mixing of “rigid” and “soft” vibrations in the boson peak region of g‐As2S3. In addition, the shift of the super‐low frequency Raman modes of “soft” nanoclusters and equivalent characteristic temperature are found to be nonlinearly dependent on the number of interconnections. Comparison with experimental Raman spectroscopic and heat capacity data indicates that the main contribution of both the LF Raman intensity and the low‐temperature anomaly of specific heat at 5.3 K comes from “soft” clusters with four and two interconnections.

Magnetic phase diagrams of the ferromagnetic Kondo lattice CePd2Al8

We report the synthesis and detailed investigation of the single crystal ${\mathrm{CePd}}_{2}{\mathrm{Al}}_{8}$. Resistivity measurements reveal typical metallic behavior at high temperatures and a plateau at about 15 K followed by a rapid drop due to successive antiferromagnetic (AFM) and ferromagnetic (FM) transitions. The specific heat and magnetic susceptibility present obvious anomalies related to both transitions. We find an extremely large magnetic anisotropy with ${\ensuremath{\chi}}_{a}/{\ensuremath{\chi}}_{b}g2000$ at 2 K. With increasing magnetic field, the AFM transition temperature is gradually suppressed and only the ferromagnetic phase remains above 500 Oe for $H\ensuremath{\parallel}a$, with an ordered moment of $1.43\phantom{\rule{0.28em}{0ex}}{\ensuremath{\mu}}_{B}$, while for $H\ensuremath{\parallel}b$ the FM transition turns into an AFM-like transition. With pressure, the two phases merge at 12.5 GPa into a possibly ferromagnetic phase, pointing to a possible critical point at higher pressures. We construct the temperature-magnetic field and temperature-pressure phase diagrams for the single crystal ${\mathrm{CePd}}_{2}{\mathrm{Al}}_{8}$.