Neodymium nickelate is a nickelate of

neodymium Neodymium is a chemical element with the symbol Nd and atomic number 60. It is the fourth member of the lanthanide series and is considered to be one of the rare-earth metals. It is a hard, slightly malleable, silvery metal that quickly tarnishes i ...

with a chemical formula NdNiO₃. In this compound, the neodymium atom is in the +3 oxidation state.

Preparation

Neodymium nickelate can be prepared by dissolving

neodymium(III) oxide Neodymium(III) oxide or neodymium sesquioxide is the chemical compound composed of neodymium and oxygen with the formula Nd2O3. It forms very light grayish-blue hexagonal crystals. The rare-earth mixture didymium, previously believed to be an el ...

and

nickel(II) oxide Nickel is a chemical element with symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive but large pieces are slow to r ...

nitric acid Nitric acid is the inorganic compound with the formula . It is a highly corrosive mineral acid. The compound is colorless, but older samples tend to be yellow cast due to decomposition into oxides of nitrogen. Most commercially available nitri ...

, followed by heating the mixture in an

oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as wel ...

atmosphere. It can also be prepared by pyrolyzing a mixture of

nickel nitrate Nickel nitrate is the inorganic compound Ni(NO3)2 or any hydrate thereof. The anhydrous form is not commonly encountered, thus "nickel nitrate" usually refers to nickel(II) nitrate hexahydrate. The formula for this species is written in two ways ...

and neodymium nitrate. It decomposes in high temperature (950 °C) by

nitrogen Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...

: :4 NdNiO₃ → 2 Nd₂NiO₄ + 2 NiO + O₂ It can also be reduced to the monovalent nickel compound NdNiO₂ by

sodium hydride Sodium hydride is the chemical compound with the empirical formula Na H. This alkali metal hydride is primarily used as a strong yet combustible base in organic synthesis. NaH is a saline (salt-like) hydride, composed of Na+ and H− ions, in co ...

at 160 °C.

Physical properties

Neodymium nickelate shows metal-insulator transition (MIT) under low temperature. The temperature at which it transforms (T_MIT) is 200K, which is higher than praseodymium nickelate (130K) but lower than samarium nickelate (400K). It transforms from

antiferromagnetism In materials that exhibit antiferromagnetism, the magnetic moments of atoms or molecules, usually related to the spins of electrons, align in a regular pattern with neighboring spins (on different sublattices) pointing in opposite directions. ...

paramagnetism Paramagnetism is a form of magnetism whereby some materials are weakly attracted by an externally applied magnetic field, and form internal, induced magnetic fields in the direction of the applied magnetic field. In contrast with this behavior, ...

. It has demonstrated to be a

first-order phase transition In chemistry, thermodynamics, and other related fields, a phase transition (or phase change) is the physical process of transition between one state of a medium and another. Commonly the term is used to refer to changes among the basic states o ...

(this applies for praseodymium nickelate as well). The temperature (T_N) can be changed by varying the NiO₆ octahedral distortion. It is the only lathanide nickelate to have the same T_MIT as T_N.

Uses

In a 2010 study, it was found that neodymium nickelate as an

anode An anode is an electrode of a polarized electrical device through which conventional current enters the device. This contrasts with a cathode, an electrode of the device through which conventional current leaves the device. A common mnemonic is ...

material provided 1.7 times the current density of typical

LSM In molecular biology, LSm proteins are a family of RNA-binding proteins found in virtually every cellular organism. LSm is a contraction of 'like Sm', because the first identified members of the LSm protein family were the Sm proteins. LSm pro ...

anodes when integrated into a commercial SOEC and operated at 700 °C, and approximately 4 times the current density when operated at 800 °C. The increased performance is postulated to be due to higher "overstoichiometry" of oxygen in the neodymium nickelate, making it a successful conductor of both ions and electrons. Neodymium nickelate can also be used in electrocatalysts, synapse transistors, photovoltaics, memory resistors, biosensors, and electric-field sensors.

References

{{nickel compounds Neodymium compounds Nickel compounds Perovskites

Preparation

Physical properties

Uses

See also

References