Negative thermal expansion of Ca<sub>2</sub>RuO<sub>4</sub> with oxygen vacancies

Negative thermal expansion of Ca₂RuO₄ with oxygen vacancies

Xu Sen¹, Hu Yangming¹, Liang Yuan^{2, †}, Shi Chenfei³, Su Yuling³, Guo Juan¹, Gao Qilong¹, Chao Mingju¹, Liang Erjun^{1, ‡}

(a) Temperature dependence of (a) resistivity and (b) the field-cooled and zero-field-cooled susceptibility of Ca₂RuO_3.87, Ca₂RuO_3.73, and Ca₂RuO_4.09. Insertion: the magnetization curves at T = 10 K.