Belkheiri, Nadji (2026) Against Purity: Nonstoichiometric Solids and the Limits of Composition-Based Ontology in Chemistry. [Preprint]
![[img]](https://philsci-archive.pitt.edu/style/images/fileicons/text.png) |
Text
Against Purity Nonstoichiometric Solids and the Limits of Composition-Based Ontology in Chemistry.docx Download (44kB) |
Abstract
This paper argues that nonstoichiometric crystalline materials challenge composition-based accounts of chemical substances, and that a pluralist, function-centered ontology is required. Drawing on examples from solid-state chemistry doped silicon (Si:P), iron-deficient wüstite (Fe1-xO), and oxygen-deficient titania (TiO₂₋δ) I show that defects such as vacancies and dopants are not mere impurities but constitutive features of material identity. I distinguish between entropy-driven and information-driven defects, providing an operational definition of the latter in terms of high mutual information between microstate configuration and macroscopic function, grounded in causal specificity (Woodward, 2010). I develop an account of structural causation, drawing on interventionist theory, to explain how vacancies exert causal influence without acting as efficient causes, while explicitly rejecting reductionist interpretations of the Hamiltonian formalism. I address three objections: (i) function as context-dependent, (ii) reduction to condensed matter physics, and (iii) the boundary problem for kind individuation. The paper defends a pluralist ontology with three logical types of chemical substances, grounded in a homeostatic property cluster account (Boyd, 1991) and tailored to contemporary defect engineering.
| Export/Citation: | EndNote | BibTeX | Dublin Core | ASCII/Text Citation (Chicago) | HTML Citation | OpenURL |
| Social Networking: |
| Item Type: | Preprint | ||||||
|---|---|---|---|---|---|---|---|
| Creators: |
|
||||||
| Keywords: | philosophy of chemistry, non-stoichiometry, crystal defects, berthollides, structural causation, natural kinds, information-driven defects, homeostatic property cluster, causal specificity, Kröger-Vink notation. | ||||||
| Subjects: | Specific Sciences > Chemistry General Issues > Philosophers of Science Specific Sciences > Physics |
||||||
| Depositing User: | Dr. Nadji Belkheiri | ||||||
| Date Deposited: | 07 Apr 2026 12:31 | ||||||
| Last Modified: | 07 Apr 2026 12:31 | ||||||
| Item ID: | 28932 | ||||||
| Subjects: | Specific Sciences > Chemistry General Issues > Philosophers of Science Specific Sciences > Physics |
||||||
| Date: | 6 April 2026 | ||||||
| URI: | https://philsci-archive.pitt.edu/id/eprint/28932 |
Monthly Views for the past 3 years
Monthly Downloads for the past 3 years
Plum Analytics
Actions (login required)
 |
View Item |
![[feed]](http://philsci-archive.pitt.edu/style/images/feed-icon-32x32.png){kind=icon}