Long-range order imposed by short-range interactions in methylammonium lead iodide: Comparing point-dipole models to machine-learning force fields

The limitation of the long-range order parameter and the necessity of the short-range order parameter for the thermodynamic description of Pb()O3-type perovskites are discussed. Based on the discussion, a statistical thermodynamic model that takes into account the configuration of the neighboring B-site ions (B′ and B″ cations) was developed. A pair-correlation approximation was used in the calculation of the configurational entropy and the long-range coulombic interaction energy between the nearest B-site ions. The theoretical calculations using Pb(Sc1/2Ta1/2)O3 (PST) and Pb(Sc1/2Nb1/2)O3 (PSN) systems indicate that the short-range order parameter persists over a wide range of temperatures examined (0–1800 K) and that there possibly occur consecutive long-range order-disorder transitions in the configuration of B-site cations. The possibility of the existence of short-range ordering above the long-range order-disorder transition temperature was also examined using the annealed PSN specimen as a typical example of Pb()O3-type perovskites.

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Short-Range and Long-Range Order in AFM–FM Exchange Coupled Compound LiCu2(VO4)(OH)2

The Journal of Physical Chemistry C ◽

10.1021/acs.jpcc.9b01534 ◽

2019 ◽

Vol 123 (29) ◽

pp. 17933-17942

Author(s):

Anatoly Koshelev ◽

Elena Zvereva ◽

Larisa Shvanskaya ◽

Olga Volkova ◽

Mahmoud Abdel-Hafiez ◽

...

Keyword(s):

Long Range ◽

Short Range ◽

Range Order ◽

Long Range Order

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Short range order and its transformation to long range order in Ni4Mo

Acta Materialia ◽

10.1016/s1359-6454(97)00314-5 ◽

1998 ◽

Vol 46 (3) ◽

pp. 881-892 ◽

Cited By ~ 39

Author(s):

Satoshi Hata ◽

Syo Matsumura ◽

Noriyuki Kuwano ◽

Kensuke Oki

Keyword(s):

Long Range ◽

Short Range ◽

Short Range Order ◽

Range Order ◽

Long Range Order

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Stochastic star formation and spiral structure

Symposium - International Astronomical Union ◽

10.1017/s0074180900243143 ◽

1985 ◽

Vol 106 ◽

pp. 551-558

Author(s):

Philip E. Seiden

Keyword(s):

Star Formation ◽

Long Range ◽

Molecular Cloud ◽

Short Range ◽

Spiral Structure ◽

Open Cluster ◽

Gravitational Interaction ◽

Range Order ◽

Ionization Front ◽

Long Range Order

Most approaches to explaining the long-range order of the spiral arms in galaxies assume that it is induced by the long-range gravitational interaction. However, it is well-known in many fields of physics that long-range order may be induced by short-range interactions. A typical example is magnetism, where the exchange interaction between magnetic spins has a range of only 10 ångströms, yet a bar magnet can be made as large as one likes. Stochastic self-propagating star formation (SSPSF) starts from the point of view of a short-range interaction and examines the spiral structure arising from it (Seiden and Gerola 1982). We assume that the energetic processes of massive stars, stellar winds, ionization-front shocks and supernova shocks, in an OB association or open cluster can induce the creation of a new molecular cloud from cold interstellar atomic hydrogen. In turn this new molecular cloud will begin to form stars that will allow the process to repeat, creating a chain reaction. The differential rotation existing in a spiral galaxy will stretch the aggregation of recently created stars into spiral features.

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