The energetics of La[sub 2[minus]x]A[sub x]NiO[sub 4[minus]y] (A = Ba, Sr)

Journal Article · Mon Mar 01 04:00:00 EST 1993 · Journal of Solid State Chemistry; (United States)

DOI:https://doi.org/10.1006/jssc.1993.1091· OSTI ID:6202175

DiCarlo, J; Mehta, A; Banschick, D; Navrotsky, A ^[1]

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1. Princeton Univ., NJ (United States)

The enthalpy of formation of the solid solution series La[sub 2[minus]x]A[sub x]NiO[sub 4[minus]y] (A = Ba, Sr; 0 [le] x 0.7 and [minus]0.18 [le] y [le] 0.04) has been measured using high-temperature reaction calorimetry. As barium or strontium is substituted for lanthanum, the enthalpy of formation from the oxides becomes more exothermic. The enthalpy of formation from the component oxides and the enthalpy of oxidation for the barium- and the strontium-doped material for a given value of x is the same within the experimental uncertainty. From the measurements of the enthalpy of oxidation for the oxygen interstitial regime (y < 0) and the oxygen vacancy regime (y > 0), the oxygen Frenkel energy for the lanthanum nickelates has been found to be 43 [+-] 20 kJ/(mole O). Based on the oxidation enthalpy measurements, the authors argue that the excess holes in lanthanum nickelate are predominantly in Ni 3d-type bands. 11 refs., 2 figs., 3 tabs.

• DOE Contract Number: FG02-89ER45394
• OSTI ID: 6202175
• Journal Information: Journal of Solid State Chemistry; (United States), Journal Name: Journal of Solid State Chemistry; (United States) Vol. 103:1; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical &amp; Physicochemical Properties
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BARIUM OXIDES
CALORIMETRY
CHALCOGENIDES
CHEMICAL REACTIONS
DISPERSIONS
ENTHALPY
FORMATION HEAT
HOLES
LANTHANUM COMPOUNDS
LANTHANUM OXIDES
MIXTURES
NICKEL COMPOUNDS
NICKELATES
OXIDATION
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
RARE EARTH COMPOUNDS
REACTION HEAT
SOLID SOLUTIONS
SOLUTIONS
STOICHIOMETRY
STRONTIUM COMPOUNDS
STRONTIUM OXIDES
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS