How to increase the size of rectangle in TikZ?

Question

I'm drawing something like a linked list, but my rectangles are pretty small, how can I increase their size?

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{calc,shapes.multipart,chains,arrows}

\begin{document}
\begin{tikzpicture}[list/.style={rectangle split, rectangle split parts=2,
    draw, rectangle split horizontal}, >=stealth, start chain]

  \node[list,on chain] (A) {1};
  \node[list,on chain] (B) {2};
  \node[list,on chain] (C) {2\nodepart{second} 3};

  \draw[*->] let \p1 = (A.two), \p2 = (A.center) in (\x1,\y2) -- (B);
  \draw[*->] let \p1 = (B.two), \p2 = (B.center) in (\x1,\y2) -- (C);

\end{tikzpicture}
\end{document}

Answer 1

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{arrows, chains, calc, positioning, shapes.multipart}

\begin{document}
\begin{tikzpicture}[
node distance = 9mm and 12mm, % <vertical distance> and <horizontal distance> between nodes
  start chain = going right,
    mw/.style = {minimum width=#1},% for shortcut in "list" shapes
  list/.style = {rectangle split, rectangle split parts=2,
                 rectangle split horizontal, draw,
                 align=center,
                 text width=7mm, % <-- have effect only on the foirst part of shape 
                 minimum height=9mm, % define height od multi part shape
                 inner sep=1mm, on chain}, 
          > = stealth, 
          ]

  \node[list] (A) {1\nodepart[mw=7mm]{two}  };
  \node[list] (B) {2\nodepart[mw=7mm]{two}  };
  \node[list] (C) {2\nodepart[mw=7mm]{two} 3};

  \node[list, below=of A] (D) {4\nodepart[mw=7mm]{two}  };% <-- observe correct syntax of "positioning" library
  \node[list] (E) {5\nodepart[mw=7mm]{two}  };
  \node[list] (F) {6\nodepart[mw=7mm]{two} 3};

  \draw[*->] ($(A.two north)!0.5!(A.two south)$) -- (B);
  \draw[*->] ($(B.two north)!0.5!(B.two south)$) -- (C);
\end{tikzpicture}
\end{document}

of course, it is simpler just increase inner sep as suggest AboAmmar in his answer, but with his solution can width of shape parts wary. Anyway, see how the code of arrows are changed. Your approach is at least strange :).

Edit: I expand above MWE with case of vertical for vertical align. Distance between nodes are determined with node distance.

I also change the numbers in shape part, that you can see, that the width of parts is independent of it content (when it is shorter then `text width, of course).

Answer 2

Like this?

When the rectangle is split horizontally, minimum height specifications will be effective, but any minimum width specifications will be ignored. And the inner sep will be applied to every part that is used. So, here I add inner sep=1em.

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{calc,shapes.multipart,chains,arrows}

\begin{document}
\begin{tikzpicture}[list/.style={rectangle split, rectangle split parts=2, draw, 
  rectangle split horizontal, inner sep=1em}, >=stealth, start chain]

  \node[list,on chain] (A) {1};
  \node[list,on chain] (B) {2};
  \node[list,on chain] (C) {2\nodepart{second} 3};

  \draw[*->] let \p1 = (A.two), \p2 = (A.center) in (\x1,\y2) -- (B);
  \draw[*->] let \p1 = (B.two), \p2 = (B.center) in (\x1,\y2) -- (C);

\end{tikzpicture}
\end{document}